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PLANT-BEEEDING 



The Horticulturist's Rule-Book 
Plant-Breeding 



\\ 



^ 



PLANT-BREEDING 



BEma FIVE LECTURES UPON THE 

AMELIORATION OF B03IESTI0 

PLANTS 



-^7 

L. H. BAILEY 







MACMILLAN AND C0„ 

AND LONDON 

1895 

All rights reserved 



Copyright, 1S95, 
By L. II. BAILEYo 



5t 



9.'^ 



WorfejoaU 3press 

J. S. Gushing & Co. — Berwick & Smitb. 
Norwood Mass. U.S.A. 



PREFACE. 

There is no subject associated with the care 
of plants respecting wliich there is so much mis- 
apprehension and imperfect knowledge, as that 
of the origination of ncAV forms. Most of the 
scattered writing touching it treats the subject 
as if all our knowledge of the matter were and 
must be derived wholly from experiment. It 
therefore recites examples of how this and that 
new form has come to be, and has made little 
attempt to discover the fundamental causes of 
the genesis of the novelties. Horticulturists 
commonly look upon each novelty as an isolated 
fact, whilst we ought to regard each one as but 
an expression of some law of the variation of 
plants. It is the common notion, too, to con- 
sider any type of plant to be essentially a fixed 
entity, and to regard any marked departure from 
the type as a phenomenon rather more to be 



Vi PREFACE. 

wondered at tlian to be explained. It is evident, 
however, that one cannot understand the pro- 
duction of new varieties until he has grasped 
some of the fundamental principles of the on- 
ward progression of the vegetable kingdom. 
Any attempt, therefore, to explain the origin of 
garden varieties, and the methods of producing 
them, must be at the same time a contribution 
to the literature of the philosophy of organic 
evolution. 

I do not know of any explicit and sustained 
attempt to account for the evolution of all gar- 
den forms, and I have therefore brought together 
in this volume the subject-matter of various 
lectures which I have been in the habit of 
giving before my students. The first and 
third lectures Avere newly elaborated the present 
summer for two addresses before the class in 
biology Avhich came together at the University 
of Pennsylvania, under the auspices of the 
American Society for the Extension of Univer- 
sity Teaching. The second lecture was first 
presented before the Massachusetts State Board 
of Agriculture, in Boston, December 1, 1891. 
In April, 1892, it Avas republished, with a bibli- 



PEEFACE. Vll 

ography of the subject, by the Rural Publishing 
Co., under the title, '' Cross-Breeding and Hybrid- 
izing." This publication is now out of print. 
I have made no attempt to collect lists or cata- 
logues of varieties, but have endeavored to make 
very brief statements of some of the underlying 
principles of the amelioration of plants, with only 
sufficient examples to fix them in the mind. 

I hope that teachers of horticulture and botany 
may find the book useful in their classes. When 
it is necessary to abridge the instruction or to 
present it to untrained students, only Lectures 
III. and V. may be used, for these contain the 
matters of greatest demonstrative importance. 

L. H. Bailey. 

Cornell University, 
Ithaca, N.Y., September 1, 1895. 



CONTENTS. 



LECTURE I. 

PAGE 

The Fact and Philosophy of Variation ... 1 

I. The Fact of Individuality 2 

The seed-individual. 
The bud-individual. 

II. Tlie Causes of Individual Differences 

a. Fortuitous variation .... 
h. Sex as a factor in the variation of plants 

c. Physical environment and variation . 

1. Variation in food supply 

2. Variation in climate . 

3. Change of seed. Bud-variation 

d. Struggle for life a cause of variation . 



III. The Choice and Fixation of Variations 



11 
12 
16 
24 

28 
29 

31 



LECTURE IL 

The Philosophy of the crossing of Plants, consid- 
ered IN Reference to their Improvement under 
Cultivation ........ 39 

I. The Struggle for Life 39 

II. The Division of Labor 42 

III. The Limits of Crossing ..... 44 

ix 



CONTENTS. 

IV. Function of the Cross .... 

a. The gradual amelioration of the type 
6. Change of seed and crossing 
c. The outright prodnction of new varieties 

V. Characteristics of C7'0sses .... 

VI. Uncertainties of Pollination 

Conclusion ...... 



PAGK 

50 
50 
59 
64 

68 
83 
86 



LECTURE III. 

How Domestic Varieties Originate .... 87 

I. Indeterminate Varieties 87 

II. Plant-breeding . ., 91 

Rule 1. Antagonistic features ... 95 
Rule 2. Quickest results in the most variable 

groups ...... 96 

Rule 3. Breed for one thing at a time , . 98 
Rule 4. Contradictory attributes ... 98 
Rule 5. Characters of the entire plant most 

important 99 

Rule 6. Plants differ in hereditary power . 104 
Rule 7. Less marked variations more impor- 
tant 105 

Rule 8. Crossing a means, not an end . . 107 
Rule 9. Choice of parents to a cross . . 109 
Rule 10. The ideal should be mental . .112 
Rule 11. Seek to produce variation in the 

desired direction . . . .114 
Rule 12. Watch for bud- varieties . . .118 
Rule 13. Progress lies in selection . . . 120 
Rule 14. The type is kept up to standard by 

continued selection . . .122 
Rule 15. The best final results are to be ob- 
tained by high tillage and intelli- 
gent selection . . . .127 



CONTENTS. 



XI 





PAGE 


III. Specific Examples .... 


. 129 


The dewberry and blackberry 


. 129 


The apple 


. 131 


Beans . 


. 135 


Cannas ...... 


. 140 



LECTURE IV. 



Borrowed Opinions ; being Extracts from the Writ- 
ings OF B. Verlot, E. a. Carriere, and W. O. 
FOCKE . 

I. Verlofs Classification of Varieties of Ornamen- 
tal Plants ....... 

II. Carriere'' s Account of Bud- varieties . 

1. General remarks upon bud- variation . 

2. List of bud -varieties ..... 

III. Focke''s Discussion of the Characteristics of 
Crosses 

1. The simple primary cross . 

Proposition 1. Similarity of crossed off 

spring . 
Proposition 2. 

offspring 
Proposition 3. 

brids . 
Proposition 4. Comparative fertility of 

hybrids 
Proposition 5. 
offspring 
ii. The progeny of crosses 

1, Progeny of crosses with their own 
pollen 



Dissimilarity of crossed 
Vegetative powers of hy 



Malformations in hybrid 



143 

143 

153 

154 
176 

215 

215 

215 
221 
225 

228 

237 
237 

238 



Xll CONTENTS. 

PAGE 

2. Derivative hybridization of crosses 

with the parent forms . . . 242 

3. Hybrids of several species . . . 244 

a. Triple hybrids .... 244 

b. Hybrids of four to six species . 246 

c. Crosses of plants grown together 247 
iii. Cross-breeds and hybrids .... 247 



LECTURE V. 

Pollination ; or How to Cross Plants .... 252 

I. The Structure of the Floiver .... 252 

II. Manipulating the Flowers 265 

GLOSSARY 282 

INDEX 286 



PLANT-BREEDING. 



LECTURE I. 

THE PACT AND PHILOSOPHY OF VARIATION, 

There is no one fact connected with horticult- 
ure which so greatly interests all persons as the 
existence of numerous varieties of plants Avhich 
seem to satisfy every need of the gardener. 
Whence came all this multitude of forms ? What 
are the methods employed in securing them ? Are 
they simply isolated facts or phenomena of gar- 
dening, or have they some relation to the broader 
phases of the evolution of the forms of life? 
These are some of the questions which occur to 
every reflective mind when it contemplates an 
attractive garden, but they are questions Avhich 
seem never to be answered. Whatever attempt 
the gardener may make at answering them is 
either befogged by an effort to define what a vari- 
ety is, or else it consists in simply reciting how a 
few given varieties came to be known. But there 

B 1 



Z FACT AND PHILOSOPHY OF VARIATION. 

must be some fundamental method of arriving at 
a conception of liow the varieties of fruits and 
flowers and other cultivated plants have origi- 
nated. If there is no such jnethod, then the 
origination of these varieties must follow no law, 
and the discussion of the whole subject is fruit- 
less. But we have every confidence in the con- 
secutive uniformity of the operations of nature, 
and it Avere strange if some underlying principle 
of the unfolding or progression of plant life does 
not dominate the origin of the varied and in- 
numerable varieties which, from time unknown, 
have responded to the touch of the cultivator. 
Let us first, therefore, make a broad survey of the 
subject in a philosophical spirit, and, later, discuss 
the more specific instances of the origination of 
varieties. 

I. The Fact of Individuality. 

There is universal difference in nature. No 
two living things are exact counterparts, for no 
two are born into exactly the same conditions and 
experiences. Every living object has individ- 
uality ; that is, there is something about it which 
enables the acute observer to distinguish it from 
all other objects, even of the same class or spe- 
cies. Every plant in a row of lettuce is different 
from every other plant, and the gardener, when 



INDIVIDUALITY. 6 

transplanting them, selects out, almost uncon- 
sciously, some plants which please him and others 
which do not. Every apple tree in an orchard of 
a thousand Baldwins is unlike every other one, 
perhaps in size or shape, or possibly in the vigor 
of growth or the kind of fruit it bears. Persons 
who buy apples for export know that fruit from 
certain regions stands the shipments better than 
the same variety from other regions ; and if one 
were to go into the orchards where these apples 
are grown, he would find the ow^ner still further 
refining the problem by talking about the merits 
of individual trees in his orchard. If one were 
to make the effort, he would find that it is pos- 
sible to distinguish differences between every two 
spears of grass in a meadow, or every two heads 
of wheat in a grain-field. 

All this is equivalent to saying that plants are 
infinitely variable. The ultimate causes of all 
this variation are beyond the purpose of the 
present discussion, but it must be evident, to 
the reflective mind, that these differences are 
the means of adapting the innumerable indi- 
viduals to every little difference or advantage 
in the environment in which they live. And if 
the object of variation is better adaptation to 
the physical conditions of life, then the same 
motive must have been present in the circum- 
stances Avhich determined the birth of the indi- 



4 FACT AND PHILOSOPHY OF VARIATION. 

vicinal. The variation in environment, therefore, 
ninst be the canse of mnch of the variation in 
plants, since differences in plants were positively 
injurious if it were possible for the conditions of 
environment to be the same. 

If no two plants are anywhere alike, then it is 
not strange if now and then some departure, more 
marked than common, is named and becomes a 
garden variety. We have been taught to feel 
that plants are essentially stable and inelastic, 
and that any departure from the type is an excep- 
tion and calls for immediate explanation. The 
fact is, however, that plants are essentially un- 
stable and jDlastic, and that variation between the. 
individuals must everywhere be expected. This 
erroneous notion of the stability of organisms 
comes of our habit of studying what we call 
species. We set for ourselves a type of plant or 
animal, and group about it all those individuals 
which are more like this type than they are like 
any other, and this group we name a species. 
Nowadays, the species is regarded as nothing 
more than a convenient and arbitrary expression 
for classifying our knowledge of the forms of 
life, but the older naturalists conceived that the 
species is the real entity or unit in nature, and we 
have not yet wholly outgrown the habit of mind 
which was born of that fallacy. Nature knows 
nothing about species ; she is concerned with the 



INDIVIDUALITY. 5 

individual, the ultimate unit. This individual she 
moulds and fits into the chinks of environment, 
and each individual tends to become the more 
unlike its birthmates the more the environments 
of the various individuals are unlike. I would 
impress upon you, therefore, as a fundamental 
conception to the discussion of the general subject 
before us, the importance of the individual plant, 
rather than the importance of the species ; for 
thereby we put ourselves as nearly as possible in 
a sympathetic attitude with nature, and, resting 
upon the ultimate object of her concern, we are 
able to understand Avhat may be conceived to be 
her motive in working out the problem of life. 
That I may still more forcibly emphasize this 
thought, let me recall to your minds the fact 
that the whole tendency of contemporary civili- 
zation, in sociology and religion, is to deal Avith 
the individual person and not with the mass. 
This is only an unconscious feeling after natu- 
ral methods of solving the most complex of 
problems, for it is exactly the means to which 
every organic thing has been subjected from the 
beginning. 

In looking for the ultimate unit or individuality 
or personality in nature, we must make a broad dis- 
tinction between the animal and the plant. Every 
higher animal is itself a unit ; it is one. It has 
a more or less definite span of life, and every part 



6 FACT AND PHILOSOPHY OF VAEIATION. 

and organ contribute a certain indispensable part 
to the life and personality of the organism. No 
part is capable of propagating itself independently 
of the sex-organs of the animal, nor is it capable 
of developing sex-organs of its own. If any part 
is removed, the animal is maimed and perhaps it 
dies. The plant, on the contrary, has no definite 
or distinct autonomy. Most plants live an indefi- 
nite existence, dependent very closely upon the 
immediate conditions in which they grow. Every 
part or branch of the plant lives largely for itself, 
it is capable of propagating and multiplying itself 
when removed from the parent plant or the colony 
of branches of which it is a member, and it de- 
velops sex-organs and other individual features 
of its own. If any branch is removed, the tree 
or plant does not necessarily suffer; in fact, the 
remaining branches usually profit by the removal, 
a fact which shows that there is a competition, 
or struggle for existence, between the different 
branches or elements of the plant. The whole 
theory and practice of pruning rest upon the fact 
of the individual unlikenesses of the branches of 
plants ; and these unlikenesses are of the same 
kind and often of the same degree as those which 
exist between different plants which are grown 
from seeds. That is, the branches of a Crawford 
peach tree, for example, differ amongst themselves 
in size, shape, vigor, productiveness, and season of 



BUD-INDIVIDUALS. 



maturity, the same as any two or more sej^arate 
Crawford trees, or any number of trees of other 
varieties, differ the one from the others. If any 
one of these branches or buds is removed and is 
grown into an independent tree, a person coukl 
not tell — if he were ignorant of its history — if 
this tree were derived from a branch or a seed. 
This proves that there is no essential unlikeness 
between branches and independent plants, except 
the mere accident that one grows upon another 
branch or plant whilst the other grows in the 
ground. But the branch may be severed and 
grown in the ground, and the seedling may be 
pulled up and grafted on the tree, and no one 
can distinguish the different origins of the two. 
And then, as a matter of fact, a very large pro- 
portion of our cultivated plants are not distinct 
plants at all, in the sense of being diff'erent crea- 
tions from seeds, but are simply the results of 
the division of branches of one original plant or 
branch. All the fruit trees of any one variety 
are obtained from the dividing up and multiplica- 
tion of the branches of the first or original tree. 

You are now curious to know how this orig- 
inal tree came to be, and this I hope to tell 
you before I am done ; but for the present, let 
me impress it upon you that it is equally possi- 
ble for it to have come from a seed, or to have 
sprung from a branch which some person had 



8 FACT AND PHILOSOPHY OF VARIATION. 

noticed to be very different from the associated 
branches in the tree-top. In other words, the 
ultimate unit or individual in growing plants is 
the bud and the bit of wood or tissue to which it 
is attached ; for every bud, like every seed, pro- 
duces an offspring which can be distinguished 
from every other offspring whatsoever. 

II. The Causes of Individual Differences. 

We have now gotten back to the starting-point, 
to that unit with which nature begins to make 
her initial differences or individualities ; that is, 
to the point where variations arise. This unit 
is the bud and the seed, — one sexless, or the 
offspring of one parent ; the other sexual, or the 
offspring of two parents. Now, inasmuch as 
the horticultural variety is only a well-marked 
variation which the gardener has chanced to 
notice and to propagate, it folloAvs that the only 
logical method of determining how garden vari- 
eties originate is to discover the means by which 
plants vary or differ one from another. 

There is probably no one fact of organic nature 
concerning the origin of which modern philoso- 
phers are so much divided as the genesis or 
reasons for the beginnings of variations or dif- 
ferences. It seems to be an inscrutable problem, 
and it would be useless, therefore, for us to at- 



FOKTUITOUS VARIATION. 9 

tempt to discover these ultimate forces in the 
present hour. Still, we must give them sufficient 
thought to enable us to satisfy our minds as to 
how far these variations may be produced by 
man ; and, in doing this, we must discover at 
least the underlying philosophy of plant variation. 
It is the natnre of organisms to be unlike their 
parents and their birthmates. Why? 

a. Fortuitous Variation. 

It will probably never be possible to refer every 
variation to a distinct cause, for it is probable that 
some of them have no antecedent. If we con- 
ceive of the forms of life as having been created 
with characters exactly uniform from generation 
to generation, then we should Ije led to look for 
a distinct occasion or cause for every departure 
from the type ; but we know, as I have already 
pointed out, that heredity by its very nature is 
not so exact as to carry over every attribute, and 
no other, of the parent to the offspring. Elas- 
ticity, plasticity, is a part of the essential consti- 
tution of all organic beings. There is probably 
no inherent tendency in organisms towards any 
ultimate or predetermined completion of form, as 
the older naturalists supposed, but simply a laxity 
or indefiniteness of constitution which is expressed 
in numberless minor differences in individuals. 



10 FACT AKD PHILOSOPHY OF VARIATION. 

That is, some variation is simply fortuitous, an 
inevitable result of the inherent plasticity of 
organisms, and it has no immediate inciting 
cause. If we Avere to assume that every minor 
difference is the result of some immediate cause, 
then we should expect every individual plant or 
animal to fill some niche, to satisfy some need, to 
produce the definite effect for which the cause 
stands. But it is apparent to one who contem- 
plates the operations of nature that very man}^ — 
certainly more than half — of the organisms which 
are born are wholly useless in the struggle for 
life and very soon perish. From tliese fortuitous 
variations nature selects, to be sure, many indi- 
viduals to be the parents of other generations 
because they chance to be fitted to live, but this 
does not affect the methods or reasons of their 
origin. It is possible that, Avhilst mau}^ of these 
mere individual differences have no direct and 
immediate cause, they may still be the result of a 
devious line of antecedent causes long since so 
much diffused and modified that they Avill remain 
forever unrecognizable ; but even if so, the fact 
still remains that these present differences or 
variations may be purposeless, and it is quite as 
well to say that they exist because it is a part 
of the organic constitution of living things that 
unlike produces unlike. 



SEX AND VARIATION. 11 

b. Sex as a Factor in the Variation of Plants. 

All plants have the faculty, either potential or 
expressed, of propagating themselves by means 
of buds, or asexual parts. This is obviously the 
cheapest and most direct possible method of proj)a- 
gation for many-membered plants, since it requires 
no special reproductive organization and energy, 
and, as only one parent is concerned in it, there 
is none of the risk of failure which resides in any 
mode of propagation in which two parents must 
find each other and form a union. There must 
be some reason, therefore, for the existence of 
such a costly mechanism as sex aside from its use 
as a mere means of propagation. It may be said 
that it exists because it is a means of more rapid 
multiplication than bud-propagation, but such is 
not necessarily the fact. There are many plants 
which jDi'oduce buds as freely as they produce 
seeds ; and then, if mere multiplication were the 
only destiny of the plant, bud-production would 
no doubt have greatly increased to have met the 
demand for new generations. The only reason 
for the existence of sex in the vegetable world 
seems to be the need for a constant rejuvenation 
and modification of the offspring by uniting the 
features of two individuals into one. There thus 
arises from every sexual union a number of new 
or different forms from which nature may select 



12 FACT AND PHILOSOPHY OF VARIATION. 

the best, — that is, those best fitted to live in the 
conditions in which they chance to be placed. 
But whilst sex is undoubtedly one of the most 
potent sources of present unlikenesses, it is not 
necessarily an original cause of individual differ- 
ences, since tlie two parties to any sexual con- 
tract must be unlike before they can produce 
unlike. When once the initial unlikenesses were 
established, every new sexual union would pro- 
duce new combinations, so that now, when every 
new form, from whatever source it appears, comes 
into existence, there are other intimately related 
forms with which it may cross. This state of 
things has existed to a greater or less degree from 
the moment sex first appeared, so that the organic 
world is now endlessly varied as the result of a 
most complex ancestry. 

The variety which sexual union has introduced 
into the world performs such an important part in 
the evolution of the forms of plants, and the prob- 
lems which it jDresents are so complex, that I shall 
leave the whole subject for an independent dis- 
cussion (Lecture II.). 

c. Physical Environment and Variation. 

Every phase and condition of physical circum- 
stances, which are not absolutely prohibitive of 
plant life, have plants which thrive in them. 



ENVIRONMENT AND VARIATION. 13 

Every soil and climate, every degree of humidity, 
hills, swamps, and ponds, — every place is filled 
with plants. Even the trunks and branches of 
trees support other plants, as epiphytes and para- 
sites. That is, plants have adapted themselves to 
every physical environment ; or, to turn the propo- 
sition around, every physical environment pro- 
duces adaptive changes in plants. There are 
those, like Weismann and his adherents, who 
contend, from purely speculative reasons, that 
these changes do not become hereditary or perma- 
nent until they have influenced a certain physio- 
logical substance which is assumed to reside in 
the reproductive regions of the organism, and 
that all those changes which have not yet reached 
this germ-plasm are, therefore, lost, or die with 
the organism. It is not necessary to combat this 
philosophy, for we know, as a matter of common 
horticultural experience, that every change or va- 
riation in any organism — unless it proceeds from 
mere accident or mutilation — may become heredi- 
tary or be the beginning of a new variety ; it is 
only necessary, therefore, for the Weismannians to 
assume — as they are always ready to do — that 
any variation which has become fixed or permanent 
has already affected the germ. Their assumption 
needs only another assumption to prove it, and, 
therefore, when we are considering merely plain 
matters of fact and experience, we need give little 



14 FACT AND PHILOSOPHY OF VARIATIOK. 

attention to the subtleties of this Neo-Darwinian 
philosophy. 

Weismann teaches that '^ acquired characters," 
or those variations which first appear in the life- 
time of the individual because of the influences of 
environment, are lost, because they have not yet 
affected the reproductive substance. But if these 
characters are induced by the effect of impinging 
environment during two or more generations, they 
may come to be so persistent that the plant can- 
not throw them off, and they become, thereby, a 
part of the hereditary and non-negotiable prop- 
erty of the species. Now, it is apparent that in 
one or another of the generations which are thus 
acted upon by the environment, there must be a 
beginning towards the fixing or hereditable per- 
manency of the new form, and we might as well 
assume that this beginning takes place in the first 
generation as in the last, since there can be no 
proof that it does not take place in either one. 
The tendency towards fixity, if it exists at all, 
undoubtedly originates at the very time that the 
variation itself originates, and it is only sophistry 
to assume that the form appears at one time and 
the tendency towards permanence at anotlier time. 
Since plants fit themselves into their circumstances 
by means of adaptive variations, we must con- 
clude that all adaptive variations have the power 
of persisting, upon occasion. 



NATAL AND POST-NATAL VARIATION. 15 

All these remarks, whilst somewhat abstruse, 
have a most hnportant bearing upon the jDhi- 
losophy of the origin of garden varieties, because 
they show, first, that changes in the conditions in 
which plants grow introduce modifications in the 
plants themselves, and second, that Avherever any 
modification occurs it is probable that it may be 
fixed and perpetuated. 

It is necessary, at this point, that we distin- 
guish between natal and post-natal variations ; 
that is, between those variations which are born 
with plants, and those which appear, as a result of 
environment, after the plant has begun to grow. 
It is commonly assumed that the form and general 
characters of the plant are already determined in 
the seed, but a moment's reflection will show that 
this is far from the truth. One may sow a hun- 
dred selected peas, for instance, all of which maj 
be alike in every discernible character. If these 
are planted in a space a foot square, it will be 
found, after two or three weeks, that some indi- 
viduals are outstripping the others, although all 
of them came up equally well and were at first 
practically indistinguishable. Tliis means that, 
because of a little advantage in food or moisture, 
or other circumstance, some plants have obtained 
the mastery and are crowding out the less fortu- 
nate ones. Here is a variation taking place before 
our very eyes, and we may be able to see the exact 



16 FACT AXD PHILOSOPHY OF VARIATIOIST. 

cause of it. Moreover, variations Avliich originate 
in this way may pass down to the offspring 
through the seeds, as in the case of " viney " peas, 
which are grown on too rich, soih All this is a 
matter of the commonest observation with the 
gardener, who is so accustomed to seeing great 
differences arise in batches of plants, all of which 
start equal and with an equal chance, that he 
never thinks to comment upon the occurrence. 
In fact, the theory and j)ractice of agriculture 
rest upon the fact that plants can be modified 
greatly by the conditions in Avhich they grow, 
after they have become thoroughly established in 
the soil. Plants may start equal, but may differ 
widely at the harvest ; and this difference may be 
controlled to a nicety by the cultivator. Every 
farmer knows, too, that the best results for the 
succeeding year are to be got only when he selects 
seeds from the best which he has been able to pro- 
duce this year. So, given uniformity or equality 
at the start, the operator moulds the individual 
plants largely at his will. 

Having noticed that j)hysical environments may 
modify plants, we are now ready to consider just 
Avhat changes in these circumstances of plant life 
are most fruitful in the production of new forms. 

1. Variation in Food Suj^ply- — The greater 
part of the changes in the physical conditions 
of life hinge upon the relative supply of food. 



FOOD SUPPLY AND VARIATION. 17 

Climbing plants assume their form because, by 
virtue of the divergence of character, they are 
enabled to fit themselves into places which other 
plants cannot occupy. They rear their foliage 
into the air, where food and sunlight are unappro- 
priated. The lower branches of the tree-top die, 
and the others thereby appropriate the more food 
and grow the faster. The entire practice of agri- 
culture is built upon the augmentation of the 
food supply. For this purpose, we set the plants 
in isolated positions, we till the ground, keep 
down other plants or weeds, add plant food to 
the soil, and prune the tree and thin the fruit. 

Thomas Andrew Knight, the chief of horticul- 
tural philosophers, appears to have been the first 
to clearly enunciate the law that excess of food 
supply is the most prolific cause of the variation 
of plants. Darwin subscribes to it without re- 
serve : ''Of all the causes which induce varia- 
bility, excess of food, whether or not changed in 
nature, is probably the most powerful." Alex- 
ander Braun, an earlier writer upon the philosophy 
of the organic world, said that " it appears rather, 
on the whole, as if the unusual conditions favor- 
able to a luxuriant state of development, afforded 
by cultivation, awakened in the plant the inward 
impulse to the display of all those variations pos- 
sible within the more or less narrowly circum- 
scribed limits of the species." It is generally 



18 FACT AND PHILOSOPHY OF VAKIATION. 

agreed by those who have given the matter much 
thought, that an excess of food above the amount 
normally or habitually received is one of the very 
chief, if not the most dominant, causes of indi- 
vidual differences in plants. Certainly every 
farmer and gardener knows that the richer the 
soil in available plant food, the stronger and the 
more abnormal and unusual his product will be. 

If, then, excess of food supply is a strong factor 
in the modification of plants, and if the one fun- 
damental aim of agriculture is to supply food in 
excess of natural conditions, it must naturally 
follow that cultivated plants should be of all 
others the most variable. This is notably true. 
Now, the first variation which usually comes of 
this liberal food supply is increase in mere big- 
ness. Probably every plant which has ever been 
cultivated has increased its stature or the size of 
some or all of its parts. Moreover, this is gener- 
ally the direct object of cultivation, — to secure 
larger herbage, fruits, seeds, or flowers. Inci- 
dentally, we find here an indubitable proof of the 
truth of the hypothesis of evolution, for if it were 
impossible for plants to vary or to assume new 
characters, there would be no cultivation and no 
agriculture; for there would be little object in 
cultivating a product if it grew equally well in 
the wild. 

This variation into mere bigness is more impor- 



BREAKING THE TYPE. 19 

tant than it may seem at first sight. All thought- 
ful horticulturists agree in believing that the first 
thing to be done in ameliorating any plant is to 
"break the type," that is, to cause it to vary. 
The particular direction of variation is not so 
important, at first; for all experience has shown 
that if once the seedlings of a plant begin to 
depart from the parental type, other and various 
modifications will soon follow. If a plant is once 
strongly modified in size, variations in shape, 
color, flavor, or other attributes are forthcoming. 
This apparent accumulation of variation seems at 
first to be incapable of scientific explanation, but 
the reasons for it are not difficult to understand 
when once they are presented. 

When plants are placed in new conditions, 
whether in the wild or in cultivation, then they 
begin to vary, but usually only in one direction 
at first, although the amount of the variation, and 
sometimes the kind, is determined very largely 
by the nature and the extent of the change in the 
conditions. This initial variation, particularly 
when plants are transferred to cultivated areas, 
is generally in the direction of greater size con- 
sequent upon the greater amount of food. This 
initial variation is generally soon followed by 
others in various directions, and from these the 
cultivator may be able to establish new varieties. 
We now ask ourselves why these many variations 



20 FACT AND PHILOSOPHY OF VARIATION. 

appear when once the type begins to modify itself. 
Consider the fact that the world is now full of 
plants. In untamed nature, not one more plant 
can grow unless another plant dies. All plants, 
therefore, are held down to narrow limits of num- 
bers, and since there are so few individuals, — 
in comparison with the seeds and buds which 
each plant produces for the chance of multiplying 
itself, — there must be, also, few kinds and degrees 
of individual differences. The farther and more 
freely a plant distributes itself, the greater must 
be the differences between the various individuals, 
because they must adapt themselves to a wider 
range of conditions. All plants are held in equi- 
librium, so to speak; but the plant organism is 
plastic by nature and quickly responds to every 
touch of environment; so, as soon as the pressure 
is removed in any direction, the plant at once 
springs into the breach. Recall the monotonous 
vegetation of the deep forest, where the battle 
of centuries has subdued all but the strongest. 
Clear away the forest, and then observe the 
fierce scramble for place and life amongst a multi- 
tude of forms Avhich spring in for an opportunity 
to better their conditions. In a few years more, 
the tender low herbs have gone. The briars and 
underbrush have usurped the land. As time goes 
on, one species after another perishes, and when 
the place is again reforested, two or three species 



EQUILIBRIUM IN NATURE. 21 

hold undisputed sway over the hind. The pop- 
lars which followed the pines have long since per- 
ished and pines again dominate the forest. Or, 
if the area were turned to pasture a few years 
after the woods were removed, the herbs and 
bushes die with the browsing, and in time the 
June grass covers the whole landscape with the 
mantle of conquest. So plants may be said to 
be always ready to fill new places in the polity 
of nature by adapting themselves to the new cir- 
cumstances as they grow into them. The appear- 
ing of any one marked variation, therefore, is 
evidence that the plant has found a ucav condi- 
tion, that the pressure is somewhat lifted, and 
that its whole plastic organization will soon re- 
spond to the new environment. It is apparent, 
then, how the simplest and rudest cultivation has 
been able, through the centuries, to so profoundly 
modify our domestic plants that we are often 
unable to recognize the forms from which they 
sprung. 

We must not forget to notice, at this point, 
that the food supply differs amongst the various 
branches of the same plant. Some branches, by 
reason of position with reference to the main 
trunk or with reference to air and sunlight, or, 
because of a better start in the beginning as a 
result of some incidental advantage, gain the 
mastery over others and crowd them out. We 



22 FACT AND PHILOSOPHY OF VARIATION. 

have already seen that no two branches on a plant 
are alike ; and we are now able to understand that 
sports or bud-varieties are no more inexplicable 
than seed- varieties are. 

Cultivation is really but an extension or intensi- 
fication of nature's methods of dealing with the 
plant world. The ultimate object of both nature 
and man is to supply more food. The variations 
which arise from the effects of mere cultivation, 
therefore, are in kind very like those which nature 
produces, the chief difference being that of degree. 
The accustomed operations of the farmer, there- 
fore, have been poAverful agents in the evolution 
of vegetable forms. The Avays in which cultiva- 
tion affords a more liberal food supply are as fol- 
lows : — 

1. By isolating the individual plant. The 
husbandman sets each plant hj itself, and then 
protects it by destroying the Aveeds or plants 
which endeavor to crowd it out. There is a 
partial exception to this in the "sowed crops," 
like the grains, and it is noticeable that variation 
in these plants is usually less marked than in the 
"hoed crops." 

2. By giving the plant the advantage of posi- 
tion, Avhereby it is allowed the most congenial 
exposure to sun and contour of land. 

3. By increasing the fertility of the soil, either 
by tillage or the direct application of plant 



MEANS OF AUGMENTING FOOD SUPPLY. 23 

food, or both. llicli and moist soils tend to 
'' break " the type, — or to cause initial varia- 
tions, — to produce verdant colors and loss of 
saccharine and pungent qualities, to induce re- 
dundant growth, and to delay maturity and 
thereby to render plants tender to cold winter 
climates. 

4. By thinning the tops of plants and the 
fruits, whereby the remaining parts receive an 
amount of food in excess of the habitual allow- 
ance. 

5. By divergence of character in associated 
plants. It is well known that a field Avhich is 
planted so thickl}^ to corn that it cannot grow 
more with profit, may still grow pumpkins be- 
tween. The pumpkins and the corn are so unlike 
in form that they complement each other, the one 
filling the niche which the other is not fitted to 
occupy. We have already seen that a copse ever 
so full of bushes may still grow vines. A meadow 
which is full of timothy may still grow clover 
in the bottom, and land which is covered with 
apple trees still grows weeds beneath. " The 
more diversified the descendants from any one 
species become in structure, constitution, and 
habits," writes Darwin, "by so much will they 
be better enabled to seize on many and widely 
diversified places in the polity of nature, and so 
be enabled to increase in numbers." 



24 FACT AND PHILOSOPHY OF VAKIATION. 

2. Variatio7i in Climate. — The fact that any 
distinct climatic region usually has plants Avhich 
are very closely related to those of other climatic 
regions in the same zone, points strongly to the 
probable profound modification of plants by cli- 
mate. And, furthermore, we should expect that if 
the food environment modifies plants, the climatic 
environment must have the same power. More- 
over, there is abundant historical and experimental 
proof that climate is capable of greatly modifying 
the vegetable kingdom. There are those who 
contradict any great effect of climate in the varia- 
tion of plants, and acclimatization has been even 
stoutly denied. These persons make the mistake 
of asking that a visible modification take place at 
once upon the transfer of a plant from one climate 
to another, and they also err in supposing that a 
plant can adapt itself to a cold climate only by 
developing a capability to withstand more cold. 
Indian corn is sometimes cited as proof that 
plants do not become acclimatized, for it is as 
tender to frost now as ever, for all that we know. 
Yet this very plant affords a most unequivocal 
example of complete acclimatization, because it 
has shortened its period of growth fully one-half 
to enable it to escape the cold of the north. 

The influence of a change of climate upon 
plants, or, what may amount to the same thing, 
the result of a transfer of plants to new climates, 



CLIMATE AND VARIATION. 25 

is so complex and so general that no detailed dis- 
cussion of the subject can be made at this time. 
It will answer our present purpose to briefly 
designate the ways in which climate modifies 
plants : — 

1. Climate greatly modifies the stature of plants. 
They become dwarfer in high latitudes and alti- 
tudes. 

2. It modifies form. Plants tend to be broader- 
headed, and also more prostrate, in high latitudes 
and altitudes. 

3. Proportionate leafiness generally increases, 
at the same time. 

4. There is, also, often a gain in comparative 
fruitfulness following transfer towards the poles. 

5. The colors of leaves, flowers, fruits, and 
seeds are greatly influenced by climate, there 
being a general tendency, in plants of temperate 
regions, to augmentation in intensity of colors as 
they are carried towards the poles. 

6. There is modification in the flavor and es- 
sential ingredients of various parts, following a 
change of climate. 

7. There is a variation in variability itself. The 
more difficult the climate in which a plant finds 
itself, the more it tends to vary to meet the uncon- 
genial environments. In the high north, many 
plants are so variable that the marks used to iden- 
tify the species in other latitudes are often lost. 



26 FACT AND PHILOSOPHY OF VARIATION. 

8. There may be a profound variation or modi- 
fication in constitution and habit by which plants 
become acclimatized, or enabled to endure a cli- 
mate at first injurious to them. This may occur 
by a variation in the constitution of the descend- 
ants, which enables them to endure directly more 
untoward conditions. It generally comes about, 
however, through a change in habit, by which 
phints, when transferred towards the poles, shorten 
their season of growth or even become annuals. 
Plants become more sensitive to spring tempera- 
tures in cold climates, so that they start relatively 
much earlier in the season — that is, at a lower 
sum-temperature — than they do in warm climates. 
Any one who has passed the springtime in both 
the North and South must have noticed how much 
more suddenly the vegetation comes forward in 
the North; and it is surprising how the spring- 
sowed crops accelerate their growth in the North 
over those in the South. 

The characters which result from a change of 
climatic environment are peculiarly within the 
control of the agriculturist, for a leading factor 
in his business is the transfer of plants far and 
Avide over the earth. So it has come that the 
staple varieties of the important grains and fruits 
are unlike in Europe and America and in all great 
geographical areas, although all the various forms 
may have sprung from one ancestor within historic 



CLIMATE AND VARrATION. 27 

times. A new country is stocked with varieties 
from tlie mother country ; but in the course of 
a few generations it is found that the varieties 
in cultivation are unlike the ones originally in- 
troduced, and from which they came. As wild 
plants have become separated from each other as 
species in the different geographical regions, so 
the cultivated plants soon begin to follow similar 
lines of divergence. In the beginning of the colo- 
nization of this country, for example, all the vari- 
eties of apples were of European origin. But in 
1817, over sixty per cent of the apples recommended 
for cultivation here were of American origin, that 
is, American-grown seedlings from the original 
stock. At the present time, f idly ninety per cent 
of the popular apples of the Atlantic states are 
American productions. The northern states of 
the Mississippi valley, to Avhich most of our east- 
ern apples are not adapted, are now witness- 
ing a similar transformation in the adaptation 
and modification of the varieties introduced 
from the East and from Russia. The newly 
introduced Japanese plums are conceded to be 
great acquisitions to our fruit-growing, but no 
doubt the best results are yet to come with the 
origination of domestic varieties of them. So 
there is an irresistible tendency towards a di- 
vergence of forms in different continental or 
geographical regions, and much of the inevi- 



28 FACT AND PHILOSOPHY OF VARIATION. 

table result is no doubt chargeable to climatic 
environment. 

3. Change of seed. Bud-variation. — I will 
pause for a moment to consider two agencies or 
phenomena which are often associated with the 
genesis of varieties. One of these is the fact 
that the simple change of seed from one locality 
to another generally gives a larger or better 
product or even more marked variation. Mere 
transfer of seed is not of itself, however, a cause 
of variation. The change is beneficial because 
it fits together characters and environments which 
are not in equilibrium with each other. A plant 
which is grown for several years in one set of con- 
ditions becomes fitted into them, so to speak, and 
is in a comparative state of rest. When the plant 
or its progeny is taken to other conditions, all the 
adjustments are broken up, and in the refitting to 
the new circumstances new or strange characters 
are apt to appear. We shall leaye this subject 
for the present, expecting to give it a fuller 
treatment in the second lecture. 

Bud-variation, or sport, is a name given to 
those branches which are so much unlike the 
normal plant in any particular that they attract 
attention. Many garden varieties are simply 
multiplications of such abnormal branches. This 
bud-variation is commonly held to be such an 
unusual and inexplicable phenomenon that it is 



yTKUGGLE FOR LIFE AND VARIATION. 29 

considered apart from all the general discnssions 
of variation. It is not, of course, a cause of vari- 
ability, but simply an effect of some antecedent, 
the same as seed- variation is. We have already 
seen that all the different branches, or even joints, 
of any plant are, in a very important sense, dis- 
tinct individuals, since every one develops its 
own organs, each is capable of reproducing itself 
independently, and each is unlike every other 
because it is acted upon differently by environ- 
ment and food supply. It is not strange, there- 
fore, that some of these individuals should uoav 
and then depart very widely from the ordinary 
type, and thereby attract the attention of a gar- 
dener, who would forthwith make cuttings or set 
grafts from the part. Every branch is a bud- 
variety, just as truly as every seedling is a seed- 
variety, — since no seedling is ever exactly like its 
parent, — and there should be no greater mystery 
connected with the sports of buds than there is 
with the variations from seeds, for the causes 
which produce the one may be and are equally 
competent to produce the other. 

d. Struggle for Life a Cause of Variation. 

We have seen that the world is full of plants. 
There is room for more only as the present indi- 
viduals die. Yet nearly every species produces 



30 FACT AND PHILOSOPHY OF VARIATION. 

a great number of seeds, and makes a most stren- 
uous effort to multiply its kind. Any one plant, 
if left to itself, is capable of covering the earth in 
a comparatively short time. A fierce struggle for 
a chance to live is therefore inevitable. This con- 
flict is most apparent to the general observer in 
the springtime, when every "herb yielding seed 
after his kind, and the tree yielding fruit, whose 
seed was in itself, after his kind," are sending 
forth a host of sturdy offspring. The very land 
seems to be pregnant with Aveeds and aspiring 
young growths. But by midsummer the num- 
bers may be less. The weaker and less fortunate 
ones have perished, and the victors have waxed 
stronger thereby. The annual and half of the 
biennial species complete their course upon the 
approach of winter, and the older perennial herbs 
are becoming weak; so in the succeeding spring- 
time there is again a fierce combat for the vacant 
places. 

One of the results of this conflict is the adjust- 
ment of plants to each other. We have seen how 
the climbing plant insinuates itself in amongst the 
shrubberies and ties them together in an impene- 
trable tangle in order that it, itself, may have a 
chance to live. So the low plants of the deep 
forest are such as have been plastic enough to 
adapt themselves to the damp shades. Thus 
plants have developed companionships or diver- 



fixatio:n^ of variations. 31 

gences in characters, by means of which, under 
the stress of circumstances, they are able to live 
together. Plants have adapted themselves to 
other plants as truly as they have adapted them- 
selves to soil or climate ; and if these latter en- 
vironments are ever the sources or causes of 
variation, then the first must be also. I must 
look upon the struggle for existence, therefore, 
as itself a cause of individual differences, since 
we know that any continued pressure from with- 
out awakens an adaptive response in the form of 
the vegetable organism. 

III. The Choice and Fixation of Varia- 
tions. 

We have now seen that every living object is 
unlike every other. In plants, even every branch 
is unlike any other branch. We have endeav- 
ored to discover some of tlie causes of these uni- 
versal differences. We have found that they 
are intimately associated with the welfare of the 
type or species, inasmuch as they appear, for 
the most part, to be the means of fitting the 
plant to live in the conditions in Avhich it is 
placed. But w^e have also seen that there are 
more individuals than can find a place to live. 
How, then, does nature choose the best from the 
poorest, and, having chosen them, how does she 



32 FACT AND PHILOSOPHY OF VARIATION. 

endeavor to fix them, or to make them more or 
less stable? 

" This preservation of favorable individual dif- 
ferences and variations, and the destruction of 
those which are injurious, I have called Natural 
Selection or the Survival of the Fittest." This 
is the philosophy which was propounded by Dar- 
win, and which will carry his name to the last 
generation of men. It looks simple enough. 
Those forms which are best fitted to live, do live, 
because they crowd out the others. Yet, this 
simple principle of natural selection was the first 
explanation of the process of evolution which 
seemed to be capable of interpreting the complex 
phenomena of the forms of organic life. For a 
time, this philosophy was thought to be the one 
fundamental motive of the evolution or progres- 
sion of life, but we are now convinced that there 
are other motives or forces at work ; but it seems 
to be indisputable that natural selection is the 
chief force underlying the evolution of plants, 
and it is the only one with which the person who 
desires to breed plants need intimately concern 
himself. 

We must now determine what a variety is. This 
is a vexed question, and one which seems never to 
be capable of an answer Avhich is satisfactory to 
the gardener. Time and again, some person has 
introduced what he considered to be a distinct new 



WHAT IS A VARIETY? 33 

variet}^ only to find that other horticulturists dis- 
pute him and declare that it is only some old vari- 
ety renamed. And yet the introducer knows that 
he has not renamed an old variety, but that he has 
simply propagated a form which appeared or origi- 
nated upon his own grounds. 

Now, let us see. Nature starts out with the 
individual to make a new form. Every individual 
is unlike every other one. When the individual 
differences are so well marked that we can readily 
describe and distinguish them, and so permanent 
that they pass down nearly intact to a few genera- 
tions, we say that Ave have a variety. If the differ- 
ences are still more marked, we say that we have a 
species. Where the variety ends and the species 
begins it may be utterly impossible to determine ; 
so we mark off at a certain point and say, arbi- 
trarily, that this much is variety and that much 
is species. Asa Gray once said to me that " species 
are judgments." Now, if there is no hard and 
fast line between the variety and the species, so 
there is none between the individual and the vari- 
ety ; for a variety is only the family of descendants 
from some one individual. That is, the idea of 
variety or species rests upon difference, but just 
how much difference shall constitute one grade or 
another is a matter of individual opinion. So, 
when two gardeners cannot agree as to whether a 
given introduction is a new variety or not, they 



34 FACT xVND PHILOSOPHY OF VARIATION. 

are having just the same difficulty that two botan- 
ists have when they cannot decide whether two 
plants are two species or one. 

It is apparent, then, that every individual plant 
is a distinct variety, only that the differences be 
tween it and other individuals may be so slight 
that they have no practical utility and cannot be 
described and recorded. Just as soon as an indi- 
vidual plant has characters so unlike its kin that 
it has some commercial value, then the plant will 
be increased by cuttings or grafts or seeds, the 
brood of offspring will be given a name, and a new 
variety is born. 

Individuals with the same general features may 
appear simultaneously in two or more places, and 
two or more men may propagate, name, and intro- 
duce them. When they are all brought together 
and compared, it will be said that they are all the 
same variety, that, according to the rules of nomen- 
clature, the brood which chanced to be named first 
must " stand " or be held to be the type of the 
variety, and that the other names must become 
synonyms. Yet some person may discover minor 
differences in them and demand that the varieties 
be kept distinct. So the see-saw goes on — a vari- 
ety is a variety so long as it answers some purpose 
in use or trade, and it is not a variety when it is so 
much like some other variety that it has no merit 
which the other does not possess. 



WHAT IS A VAKIETY? 35 

As soon as a plant appears with some feature 
which is more desirable than anything which has 
preceded it, therefore, it may be made the begin- 
ning of a new variety. Man chooses it, and then 
propagates it. This is human selection. If nat- 
ure did the same, it would be natural selection. 

Now, how does nature preserve or fix tliis type ? 
She does not preserve it ! She simply chooses it 
as a beginning and gradually modifies it and shapes 
it into the form which she needs. She has no per- 
manent forms. There is a general onward pro- 
gression of every type either towards other types 
or towards extinction. We have seen that nature 
is constantly choosing and selecting. If she selects 
an individual for the beginning of a race, then 
she selects just as keenly from every offspring of 
that individual, and so on to the end of time. The 
process never stops. So nature fixes her forms by 
keeping them moving, growing, constantly develop- 
ing farther away from their beginnings. 

Now, man does the same thing. A plant in a 
cabbage row pleases him. It has a solid, small 
head and stout stem. He stores it away for seed. 
Amongst the offspring, perhaps fifty per cent are 
as good as the parent. These are saved. So the 
process goes on, from season to season. In four 
or five generations of plants, he finds that ninety 
per cent of the seeds "come true." Then he 
names it and introduces it. It is well advertised 



36 FACT AND PHILOSOPHY OF VAEIATION. 

in the seed catalogues. Many people buy the 
seeds. Some of tliese persons will grow their 
own seed, and every one of them has a different 
ideal in mind when selecting the seed parents. 
So, in the course of a few years, it is found that 
there are really several more or less different 
forms going under the same name. Some person 
may observe this difference and legitimately in- 
troduce one or more of the forms as distinct 
varieties. Some other person, however, who has 
known the history of the stock and who is not 
aware that varieties pass into other forms, objects 
to the new names and declares that the introducer 
is imposing upon the public. 

This is the history of ninety-nine out of every 
hundred varieties which are habitually propa- 
gated by seeds, like the kitchen-garden vege- 
tables and the annual flowers. Some peculiar 
individual, appearing we know not why, is dis- 
covered, and seeds are saved and selection — 
perhaps unconscious selection — begins. After 
a time the variety is broken up into several, or 
else, if it varies only slightly into divergent 
forms, the whole body or generations of the 
variety move onward, gradually departing from 
the initial type until it is no longer the same, 
although it may still bear the same name. The 
life of seed-varieties, in their pure and original 
form, is very short. Even the best of them are 



THE PASSING OF VARIETIES. 37 

usually measured by one or two decades. They 
run out or pass out by variation, into other forms. 
The Trophy tomato is not the Trophy tomato 
which Avas introduced over twenty years ago, 
although it bears the old name and is a direct 
descendant of the first stock. 

In plants multiplied by buds — that is, by bud- 
ding, grafting, cuttings, tubers, and the like — 
there is less variation in the offspring than in 
those propagated by seeds. Yet we have seen 
that no two Baldwin apple trees — all of which 
are but divisions, more or less remote, of the one 
original tree — are alike, and now and then one 
branch of a fruit tree may " sport," or develop a 
strange bud-variety. We know, too, that the 
same variety of fruit tree takes on different 
characters in different geographical regions, so 
that the Greening apple is no longer the Green- 
ing of Rhode Island in the West and South. So, 
it is apparent that even when we divide a plant 
into many parts and distribute the members far 
and wide, and when there is no occasion for con- 
cerning ourselves with fixing the type, — even 
here there is variation. In some cases, particu- 
larly in those in which we multiply the plant by 
dividing abnormally developed parts, there is a 
tendency to scatter or to vary in many directions, 
and also a tendency to run out by degeneration. 
This is admirably true of the potato, varieties of 



38 FACT AND PHILOSOPHY OF VARIATION. 

which, m ten years or less, become so mixed in 
their characters, through rapid variation and de- 
terioration, that we must return to seedling pro- 
ductions for a new start. 

The gist of all this is the fact that nature does 
not make new varieties or species by leaps and 
bounds or sudden starts, but that she gradually 
produces the new out of the old, so slowly that 
were a man to live a thousand years he might 
note little change in the grosser features of plants. 
She employs crossing, the changes in all the varied 
conditions of life, and whatever other forces she 
may possess, to give small differences between 
individuals. Then the slow and cumulative 
process of selection carries the work forward 
forever. Man must follow the same course, in 
the main. He is only rarely the direct means of 
originating variations. He finds them amongst 
the normal plants of the field and garden. His 
skill and science are exercised in the selection 
and so-called breeding of the offspring, not in 
the original genesis of the new form. It is only 
in those plants which he multiplies by simple 
division that he gains much direct profit by 
crossing or hybridizing. It is the slow and pa- 
tient care and selection, day by day, which per- 
manently ameliorate and improve the vegetable 
world. Nature starts the work ; man may com- 
plete it. 



LECTURE II. 

THE PHILOSOPHY OF THE CROSSING OF PLANTS, 
CONSIDERED IN REFERENCE TO THEIR IMPROVE- 
MENT UNDER CULTIVATION. 

I. The Struggle for Life. 

It is now understood that the specific forms or 
groups of plants have been determined largely by 
the survival of the fittest in a long and severe 
struggle for existence. The proof that this strug- 
gle everywhere exists becomes evident upon a 
moment's refiection. We know that all organisms 
are eminently variable. In fact, no two plants or 
animals in the world are exactly alike. We also 
know that very few of the whole number of seeds 
which are produced in any area ever grow into 
plants. If all the seeds produced by the elms 
upon Boston Common in any fruitful year were to 
grow into trees, this city would become a forest as 
a result. If all the seeds of the rarest orchid in 
our woods were to grow, in a few generations of 
plants even our farms would be overrun. If all 
the rabbits which are born were to reach old age, 
and all their offspring were to do the same, in less 
than ten years every vestige of herbage would be 

39 



40 PHILOSOPHY OF CROSSING PLANTS. 

swept from the country, and our farms would 
become barren. There is, then, a wonderful latent 
potency in these species ; but the same may be 
said of every species of plant and animal, even of 
man himself. If one species of plant would over- 
run and usurp the land if it increased to the full 
extent of its possibilities, what would be the result 
if each of the two thousand and sixty-one plants 
known to inhabit Middlesex County were to do the 
same ? And then fancy the result if each of the 
animals, from rabbits and mice to frogs and leeches, 
were to increase without check ! The plagues of 
Egypt would be insignificant in the comparison ! 

The fact is, the world is not big enough to hold 
the possible first offspring of the plants and ani- 
mals at this moment living upon it. Struggle for 
existence, then, is inevitable, and it must be severe. 
It follows as a necessity that those seeds grow or 
those plants live which are best fitted to grow and 
live, or which are fortunate enough to find a con- 
genial foothold. It would appear, at first thought, 
that much depends upon the accident of falling 
into a congenial place, or one unoccupied by other 
plants or animals ; but, inasmuch as scores of 
plants are contending for every unoccupied place, 
it follows that everywhere only the fittest can 
germinate or grow. In the great majority of cases, 
plants grow in a certain place because they are 
better fitted to grow there, to hold their own, than 



STRUGGLE FOR EXISTENCE:. 41 

any other plants are ; and the instances are rare in 
which a phmt is so fortunate as to find an un- 
occupied place. We are apt to think that plants 
chance to grow where we find them, but the chance 
is determined by law, and therefore is not chance. 

Much of the capability of a plant to persist 
under all this struggle depends, therefore, upon 
how much it varies ; for the more it varies the 
more likely it is to find places of least struggle. 
It groAvs under various conditions, — in sun and 
shade, in sand and cla}- , by the sea-shore or upon 
the hills, in the humidity of the forest or the 
aridity of the plain. In some directions it very 
likely finds less struggle than in others, and in 
these directions it expands itself, multiplies, and 
gradually dies out in other directions. So it 
happens that it tends to take on new forms, or to 
undergo an evolution. In the meantime, all the 
intermediate forms, which are at best only indif- 
ferently adapted to their conditions, tend to dis- 
appear. In other words, gaps appear which we 
call " missing links." The weak links break and 
fall away, and what was once a chain becomes a se- 
ries of rings. So the " missing links " are amongst 
the best proofs of evolution. 

The question now arises as to the cause of these 
numerous variations in animals and plants. Why 
are no two individuals in nature exactly alike? 
The question is exceedingly difiicult to answer. 



42 PHILOSOPHY OF CROSSING PLANTS. 

It was once said that plants vary because it is 
their nature to vary ; that variation is a necessary 
function, as much as ofrowth or fructification. 
This really remov^es the question beyond the reach 
of philosophy ; and direct observation leads us to 
think that some variation, at least, is due to ex- 
ternal circumstances. (See Lecture I.) We are 
now looking for the cause of variation as a part of 
the scheme of evolution; and we are wondering if 
the varied surroundings, or, as Darwin put it, the 
" changed conditions of life," may not actually 
induce variability. This conclusion would seem 
to follow from the fact of the severe and universal 
struggle in nature whereby plants are constantly 
forced into new and strange conditions. But there 
is undoubtedly much variation which has sprung 
from more remote causes, one of which it is my 
purpose to discuss here. 

II. The Division of Labor. 

In the lowest animals and plants — which are 
simply single cells — the species multiplies by 
means of simple division or by budding. One in- 
dividual, of itself, becomes two, and the two are 
therefore recasts of the one. But, as organisms 
multiplied and conditions became more complex, 
that is, as struggle increased, there came a differen- 
tiation in the parts of the individual, so that one 



DIVISION OF LABOR. 43 

cell or one cluster of cells performed one labor 
and other cells performed other labor; and this 
tendency resulted in the development of organs. 
Simple division, therefore, could no longer repro- 
duce the whole complex individual ; and, as all 
organs are necessary to the existence of life, the 
organism may die if it is divided. Along with 
this specialization came the differentiation into 
sex ; and sex clearly has two offices : to hand over, 
by some mysterious process, the complex organ- 
ization of the parent to the offspring, and also to 
unite the essential characters or tendencies of two 
beings into one. The second office is manifestly 
the greater, for, as it unites two organizations into 
one, it insures that the offspring is somewhat un- 
like either parent, and is therefore better fitted to 
seize upon any place or condition new to its kind. 
And as the generations increase, the tendency 
to variation in the offspring must be constantly 
greater, because the impressions of a greater num- 
ber of ancestors are transmitted to it. I have said 
that this office of sex to induce variation is more 
important than the mere fact of reproduction of a 
complex organization ; for it must be borne in 
mind that the complexity of organization is itself 
a variation and adaptation made necessary by the 
increasing struggle for existence. 

If, therefore, the philosophy of sex is to promote 
variation by the union of different individuals, it 



44 PHILOSOPHY OF CKOSSING PLANTS. 

must follow that the greatest variation must come 
from parents considerably unlike each other in 
their minor characters. Thus it comes that in- 
breeding tends to weaken a type, and cross-breeding 
tends to strengthen it. And at this point we meet 
the particular subject which I am to present to 
you. I have introduced you to this preliminary 
sketch because I contend that Ave can understand 
crossing ouly as we make it a part of the general 
philosophy of nature. There are the vaguest 
notions concerning the possibilities of crossing, 
some of which I hope to correct by presenting the 
subject in its relations to the general aspects of 
the vegetable world. 

We are now prepared to understand that crossing 
is good for the species, because it constantly revi- 
talizes offspring Avith the strongest traits of the 
parents, and ever presents ncAv combinations which 
enable the individuals to stand a better chance of 
securing a place in the polity of nature. The fur- 
ther discussions of the subject are such as have to 
do Avith the extent to AAdiich crossing is possible and 
advisable, and the general results of the operation. 

III. The Limits of Crossing. 

If crossing is good for the species, Avhich philoso- 
phy and direct experiment abundantly show, it is 
necessary at once to find out to Avhat extent it can 



LIMITS OF CHOSSING. 45 

be carried. Does the good increase in proportion 
as the cross becomes more violent, or as the parents 
are more and more unlike ? Or do we soon find a 
limit beyond which it is not profitable or even 
possible to go, — a point at which we say that " an 
inch is as good as an ell " ? If great variability is 
good for the species in the struggle for existence, 
and if crossing induces variability because of the 
union of unlike individuals, it would seem to follow 
that the more unlike the parents are, the greater 
will be the variation in offspring and the more the 
type will prosper ; and, carrying this thought to 
its logical conclusion, we should expect to find that 
the most closely related plants would constantly 
tend to refuse to cross, because the offspring of 
them would be little variable and therefore little 
adapted to the struggle for existence ; while the 
most widely separated plants would constantly tend 
to cross more and more, because their offspring 
would present the greatest possible degrees of dif- 
ferences. We should expect, for instance, that a 
Baldwin apple would be less likely to cross with a 
Greening than it is to cross with a peach or a gourd. 
And, if we should carry our thought a step farther, 
we should at once see that this crossing between 
different species would soon fill in all differences 
between those species, and that definite specific 
types would cease to exist. This would be pande- 
monium, and crossing would be the cause of it ! 



46 PHILOSOPHY OF CROSSING PLANTS. 

Now, essentially this reasoning has been ad- 
vanced to combat the evolution of plants and 
animals by means of natural selection ; and this 
proposition that intermixing must constantly tend 
to obliterate all differences between plants and to 
prevent the establishment of well-marked types, 
has been called the " swamping effects of inter- 
crossing." It is exceedingl}^ important that we 
consider this question, for it really lies at the 
foundation of the improvement of cultivated plants 
by means of crossing, as well as the persistence 
and evolution of varieties and species under wholly 
natural conditions. 

We find, however, that distinct species, as a rule, 
refuse to cross ; and the first question which natu- 
rally arises is. What is the immediate cause of the 
refusal of plants to cross ? How does this refusal 
express itself? It comes about in many wa3^s. 
The commonest cause is the positive refusal of 
a plant to allow its ovules to be impregnated by 
the pollen of another plant. The pollen will not 
" take." For instance, if we apply the pollen of a 
Hubbard squash to the flower of the common field 
pumpkin, there will simply be no result, — the 
fruit will not form. The same is true of the pear 
and the apple, the oat and the wheat, and most 
very unlike species. Or the refusal may come in 
the sterility of the cross or hj^brid : the pollen may 
" take " and seeds may be formed and the seeds 



BARRIERS TO INTERCROSSIKG. 47 

may grow, but the plants which they produce may 
be wholly barren, sometimes even refusing to pro- 
duce flowers as well as seeds, as in the instance of 
some hybrids between the Wild Goose plum and 
the peach. Sometimes the refusal to cross is due 
to some difference in the time of blooming or some 
incompatibility in the structure of the flowers. But 
it is enough for our purpose to know that there are 
certain characters in Avidely dissimilar plants which 
prevent intercrossing, and that these characters are 
just as positive and just as much influenced by 
change of environment and natural selection as are 
size, color, productiveness, and other characters. 

Here, then, is the suf^cient answer to the 
proposition that intercrossing must swamp all 
natural selection, and also the explanation of the 
varying and often restricted limits within which 
crossing is possible. That is, the checks to cross- 
ing have been developed through the principle 
of universal variability and natural selection, as 
has been shown by Darwin and Wallace. Plants 
vary in their reproductive organs and powers just 
the same as they do in other directions ; and when 
such a variation is useful it is perpetuated, and 
when hurtful it is lost. Suppose that a certain 
well-marked individual of a species should find an 
unusually good place in nature, and it should mul- 
tiply rapidly. Crosses would be made between 
its own offspring and perhaps between those off- 



48 PHILOSOPHY OF CROSSING PLANTS. 

spring and itself in succeeding ^^ears ; and it is 
fair to suppose that some of the crosses woukl be 
particuharly well adapted to the conditions in 
which the parent grew, and these would constantly 
tend to perpetuate themselves, while less adaptive 
forms would constantly tend to disappear. Now, 
the same thing Avould take place if this individual 
or its adaptive offspring Avere to cross with the 
main stock of the parent species ; for all the off- 
spring of such a cross which are intermediate in 
character and therefore less adapted to the new con- 
ditions would tend to disappear, and the two t3^pes 
would, as a result, become more and more fixed and 
the tendency to cross would constantly decrease. 

The refusal to cross, therefore, becomes a posi- 
tive character of separation, and the "missing 
links " which result from crossing are no more 
or no less inexplicable than the "missing links" 
due to simple selection ; or, to put the case more 
accurately, natural selection weeds out the ten- 
dency to promiscuous crossing, when it is hurtful, 
in just the same manner that it weeds out any 
other injurious tendency. It makes no difference 
in what way this tendency expresses itself, whether 
in some constitutional refusal to cross, — if such 
exists, — or in, infertility of offspring, or in differ- 
ent times of blooming: all equally come under the 
power of natural selection. We are apt to look 
upon infertility as the absence of a character, a 



HYBRIDS KAKELY ITSEFUL. 49 

sort of a negative feature which is somehow not 
the legitimate property of natural selection ; but 
such is not the case. We are perhaps led the 
more to this feeling because the word infertility 
is itself negative, and because we associate full pro- 
ductiveness with the positive attributes of plants. 
But loss of productiveness is surely no more a sub- 
ject of wonder than loss of color or size, if there is 
some corresponding gain to be accomplished. In 
fact, we see, in numerous plants which propagate 
easily by means of runners and suckers, a very low 
degree of productiveness, that is, infertility. 

Now, if this reasoning is sound, it leads us to 
conclusions quite the reverse of those held by the 
advocates of the swamping effects of intercrossing, 
and these conclusions are of the most vital impor- 
tance to every man who tills the soil. The logical 
result is simply this : the best results of crossing 
are obtained, as a rule, when the cross is made be- 
tween different individuals of the same variety, 
or at farthest, between different individuals of the 
same species. In other words, hybrids — or crosses 
between species — are rarely useful in nature, and 
it follows that the more unlike the species the less 
useful will be the hybrids. This, I am aware, is 
counter to the notions of most horticulturists, and, 
if true, must entirely overthrow our common think- 
ing upon this subject. But I think that I shall be 
able to show that observation and experiment lead 



50 PHILOSOPHY OF CKOSSING PLANTS. 

to the same conclusion to which our philosophy 
has brouQ'ht us. 



IV. Function of the Cross. 

a. The G-radual Amelioration of the Tt/jje. 

At this point we must ask ourselves Avhat we 
mean by "best results." I take this phrase to 
refer to those plants which are best fitted to sur- 
vive in the struggle for existence, those whicli are 
most vigorous or most productive or most hardy, 
or which possess any well-marked character or 
characters Avhich distinguish them in virility from 
their fellows. We commonly associate the term 
more particularly with marked vigor and produc- 
tiveness ; these are the characters most useful in 
nature and also in cultivation, the ones which Ave 
oftenest desire to obtain. Another type of varia- 
tion Avhich we constantly covet is something which 
Ave can call a new character, Avhich will lead to the 
production of a new cultural variety, and Ave are 
always looking to this as the legitimate result of 
crossing. We have forgotten — if, indeed, we ever 
kncAv — that the commoner, all-pervading, more 
important function of the cross is to infuse some 
new strength or power into the offspring, to improve 
or to perpetuate an existing variety, rather than to 
create a new one. Or, if a ncAv one is created, it 



FUNCTION OF THE CROSS. 51 

comes from the gradual passing of one into another, 
an inferior variety into a good one, a good one into 
a superlative one. So nature employs crossing in 
a process of slow or gradual improvement, one step 
leading to another, and not in any bold or sudden 
creation of new forms. And there is evidence to 
show that something akin to this must be done to 
secure the best and most permanent results under 
cultivation. The notion is somehow firmly rooted 
in the popular mind that new varieties can be pro- 
duced with the greatest ease by crossing parents of 
given attributes. There is something captivating 
about the notion. It smacks of a somewhat magic 
power Avhich man evokes as he passes his wand 
over the untamed forces of nature. But the wand 
is often only a gilded stick, and is apt to serve no 
better purpose than the drum major's pretentious 
baton I 

Let me say further that crossing alone can 
accomplish comparatively little. The chief power 
in the evolution or progression of plants appears 
to be selection, or, as Darwin puts it, the law of 
"preservation of favorable individual differences 
and variations, and the destruction of those Avhich 
are injurious." Selection is the force which aug- 
ments, develops, and fixes types. Man must not 
only practice a judicious selection of parents from 
which the cross is to come, which is in reality but 
the exercise of a choice, but he must constantly 



52 PHILOSOPHY OF CROSSING PLANTS. 

select the best from among the crosses, iii order to 
maintain a high clesfree of usefulness and to make 
any advancement ; and it sometimes happens that 
the selection is mucli more important to the culti- 
vator than the crossing. I do not wish to discour- 
age the crossing of plants, but I do desire to dispel 
the charm which too often hangs about it. 

Further discussion of this subject naturally falls 
under two heads : the improvement of existing 
types or varieties by means of crossing, and the 
summary production of new varieties. I have 
already stated that the former office is the more 
important one, and the proposition is easy of proof. 
It is the chief use which nature makes of crossing, 
— to strengthen the type. Think, for instance, of 
the great rarity of hybrids or pronounced crosses 
in nature. No doubt all the authentic cases on 
record could be entered in one or two volumes, but 
a list of all the individual plants of the world 
could not be compressed into ten thousand volumes. 
There are a few genera, in which the species are 
not well defined or in which some character of 
inflorescence favors promiscuous crossing, in which 
hybrids are conspicuous ; but even here the num- 
ber of individual hybrids is very small in compari- 
son to the whole number of individuals. That is, 
the. hybrids are rare, while the parents may be 
common. This is well illustrated even in the 
willows and oaks, in which, perhaps, hybrids are 



RARITY OF HYBRIDS. 5S 

better known than in any other American plants. 
The great genus carex or sedge, which occurs in 
great numbers and many species in almost every 
locality in New England, and in which the species 
are particularly adapted to intercrossing by the 
character of their inflorescence, furnishes but few 
undoubted hybrids. Among one hundred and 
eighty-five species and prominent varieties inhabit- 
ing the northeastern states, there are only eleven 
hybrids recorded, and all of them are rare or local, 
some of them having been collected but once. 
Species of carex of remarkable similarity may grow 
side by side for years, even intertangled in the 
same clump, and yet produce no hybrid. These 
instances prove that nature avoids hybridization, 
— a conclusion at which we have already arrived 
from philosophical considerations. And we have 
reason to infer the same conclusion from the fact 
that flowers of different species are so constructed 
as not to invite intercrossing. But, on the other 
hand, the fact that all higher plants habitually 
propagate by means of seeds, which is far tlie most 
expensive to the plant of all methods of propa- 
gation, while at the same time most flowers are so 
constructed as to prevent self-fertilization, proves 
that some corresponding good must come from 
crossing within the limits of the species or variety ; 
and there are purely philosophical reasons, as we 
have seen, which warrant a similar conclusion. 



54 PHILOSOPHY OF CROSSING PLANTS. 

But experiment lias given us more direct proof of 
our propositions, and we shall now turn our atten- 
tion to the garden. 

Darwin was the first to show that crossing within 
the limits of the species or variety results in a con- 
stant revitalizing of the offspring, and that this is 
the particular ultimate function of cross-fertiliza- 
tion. Kolreuter, Sprengel, Knight, and others had 
observed many, if, indeed, not all, the facts obtained 
by Darwin ; but they had not generalized upon 
them broadl}^ and did not conceive their relation 
to the complex life of the vegetable world. Dar- 
win's results are, concisely, these ; self-fertilization 
tends to weaken the offspring ; crossing between 
different plants of the same variety gives stronger 
and more productive offspring than arises fi'om 
self-fertilization ; crossing between stocks of the 
same variet}^ grown in different places or under dif- 
ferent conditions gives better offspring than cross- 
ing between different plants grown in the same 
place or under similar conditions ; and his re- 
searches have also shown that, as a rule, flowers 
are so constructed as to favor cross-fertilization. 
In short, he found, as he expressed it, that " nature 
abhors perpetual self-fertilization." Some of his 
particular results, although often quoted, will be 
useful in fixing these facts in our minds. Plants 
from crossed seeds of morning-glory exceeded in 
height those from self-fertilized seeds as 100 exceeds 



IKCREASED A^IGOR OF CKOSS-BEEEDS. 55 

76, in the first generation. Some flowers from tliese 
plants were self-pollinated and some were crossed, 
and in this second generation the crossed plants 
were to the uncrossed as 100 is to 79 ; the opera- 
tion was again repeated, and in the third generation 
the figures stand 100 to 68 ; fourth generation, tlie 
plants having been grown in midwinter, when none 
of them did well, 100 to 86 ; fifth generation, 100 
to 75 ; sixth generation, 100 to 72 ; seventh genera- 
tion, 100 to 81 ; eighth generation, 100 to 85 ; ninth 
generation, 100 to 79 ; tenth generation, 100 to 
54. The average total gain in height of the 
crossed over the uncrossed was as 100 to 77, or 
about 30 per cent. There was a corresponding 
gain in fertility, or the number of seeds and seed- 
pods produced. Yet, striking as the results are, 
they were produced by simply crossing between 
plants grown near together, and under what would 
ordinarily be called uniform conditions. In order 
to determine the influence of crossing with fresh 
stock, plants of the same variety were obtained 
from another garden, and these were crossed with 
the ninth generation mentioned above. The off- 
spring of this cross exceeded those of the other 
crossed plants as 100 exceeds 78, in height; as 100 
exceeds 57, in the number of seed-pods ; and as 100 
exceeds 51, in the weight of the seed-pods. In 
other words, crosses between fresh stock of the same 
variet}^ were nearl}^ 30 per cent more vigorous than 



56 PHILOSOPHY OF CROSSING PLANTS. 

crosses between plants grown side by side for some 
time and over 44 per cent more vigorous than 
plants from self-fertilized seeds. On the other 
hand, experiments showed that crosses between 
different flowers upon the same plant gave actu- 
ally poorer results than offspring of self-fertilized 
flowers. It is evident, from all these figures, that 
nature desires crosses between plants, and, if jdos- 
sible, between plants grown under somewhat dif- 
ferent conditions. All the results are exceedingly 
interesting and important; and there is every 
reason to believe that, as a rule, similar results can 
be obtained with all plants. 

Darwin extended his investigations to many 
plants, only a few of which need be discussed here. 
Cabbage gave pronounced results. Crossed plants 
were to self-fertilized plants in weight as 100 is 
to 37. A cross was now made between these 
crossed plants and a plant of the same variety 
from another garden, and the difference in weight 
of the resulting offspring was the difference be- 
tween 100 and 22, showing a gain of over 350 per 
cent, due to a cross with fresh stock. Crossed 
lettuce plants exceeded uncrossed in lieight as 
100 exceeds 82. Buckwheat gave an increase in 
weight of seeds as 100 to 82, and in height of 
plants as 100 to 69. Beets gave an increase in 
height represented by 100 and 87. Maize, when 
full grown, from crossed and uncrossed seeds. 



INCREASED VIGOR OF CROSS-BREEDS. 57 

gave the differences in height between 100 and 91. 
Canary-grass gave similar results. 

I have obtained results as well marked as these 
upon a large and what might be called a commer- 
cial scale. I raised the plants during the first 
generation of seeds from known parentage, the 
flowers from which they came having been care- 
fully pollinated by hand. In some instances the 
second generations were grown from hand-crossed 
seeds, but in other cases the second generations 
were grown from seeds simply selected from the 
first-year patches. As the experiments have been 
made in the field and upon a somewhat extensive 
scale, it was not possible to accurately measure 
the plants and the fruits from individuals in all 
cases ; but the results have been so marked as to 
admit of no doubt as to their character. In 1889 
several hand-crosses w^re made among egg-plants. 
Three fruits matured, and the seeds from them 
were grown in 1890. Some two hundred plants 
were grown, and they were characterized through- 
out the season by great sturdiness and vigor of 
growth. They grew more erect and taller than 
other plants near by grown from commercial seeds. 
They were the finest plants which I had ever seen. 
It was impossible to determine productiveness, 
from the fact that our seasons are too short for 
egg-plants, and only the earliest flowers, in the 
large varieties, perfect their fruit, and the plant 



58 PHILOSOPHY OF CROSSING PLANTS. 

blooms continuously througli the season. In order 
to determine how mucli a plant will bear, it must 
be grown until it ceases to bloom. When frost 
came, I could see little difference in productive- 
ness between these crossed plants and commercial 
plants. A dozen fruits were selected from various 
parts of this patch, and in 1891 about twenty-five 
hundred plants were grown from them. Again 
the plants Avere remarkably robust and healthy, 
with fine foliage, and they grew erect and tall, — 
an indication of vigor. They were also very pro- 
ductive ; but, as the cross had been made between 
unlike varieties, and the offsprings were therefore 
unlike either parent, I could not make an accurate 
comparison. But they compared well with com- 
mercial egg-plants, and I am satisfied that they 
would have shown themselves to be more produc- 
tive than common stock could they have grown a 
month or six weeks longer. Professor Munson, of 
the Maine Agricultural College, grew some of this 
crossed stock in 1891, and he told me that it was 
better than any commercial stock in his gardens. 

In extended experiments in the crossing of 
pumpkins, squashes, and gourds, carried on dur- 
ing several years, increase in productiveness due 
to crossing has been marked in many instances. 
Marked increase in productiveness has been ob- 
tained from tomato crosses, even when no other 
results of crossing could be seen. 



BENEFITS FROM CHANGE OF SEED. 59 

b. Change of Seed and Crossing. 

Bearing in mind these good influences of cross- 
ing, let us recall another series of facts following 
the simple change of seed. Almost every farmer 
and gardener at the present day feel that an 
occasional change of seed results in better crops, 
and there are definite records to show that such 
is often the case. In fact, I am convinced that 
much of the rapid improvement in fruits and vege- 
tables in recent years is due to the practice of 
buying plants and seeds so largely of dealers, by 
means of which the stock is often changed. Even 
a slight change, as between farms or neighboring 
villages, sometimes produces marked results, such 
as more vigorous plants and often more fruitful 
ones. We must not suppose, however, that be- 
cause a small change gives a good result, a violent 
or very pronounced change gives a better one. 
There are many facts on record to show that great 
changes often profoundly influence plants, and 
when such influence results in lessened vigor or 
lessened productiveness we call it an injurious one. 
Now, this injurious influence may result even 
when all the conditions in the new place are 
favorable to the health and development of the 
plant; it is an influence which is wholly indepen- 
dent, so far as we can see, of any condition which 
interferes injuriously with the simple processes of 



60 PHILOSOPHY OF CROSSING PLANTS. 

growth. Seeds of a native pbysalis or liusk-tomato 
were sent to me from Paraguay in 1889 by Dr. 
Thomas Morong, then travelling in that country. 
I grew it both in the house and out of doors, and 
for two generations was unable to make it set 
fruit, even though the flowers were hand-polli- 
nated ; yet the plants were healthy and grew 
vigorously. The third generation grown out of 
doors set fruit freely. This is an instance of the 
fact that very great changes of conditions may 
injuriously affect the plant, and an equally good 
illustration of the power to overcome these condi- 
tions. Now, there is great similarity between the 
effects of slight and violent changes of conditions 
and small and violent degrees of crossing, as both 
Darwin and Wallace have pointed out, and it is 
pertinent to this discussion to endeavor to dis- 
cover why this similarity exists. 

It is well proved that crossing is good for the 
resulting offspring, because the differences be- 
tween the parents carry over new combinations 
of characters or at least new powers into the 
crosses. It is a process of revitalization, and the 
more different the stocks in desirable characters 
within the limits of the variety, the greater is 
the revitalization ; and frequently the good is of 
a more positive kind, resulting in pronounced 
characters which may serve as the basis for new 
varieties. In the cross, therefore, a new combina- 



BENEFITS FROM CHANGE OF SEED. 61 

tion of characters or a new power fit it to live 
better than its parents in the conditions under 
which they lived. 

In the case of change of stock we find just the 
reverse, which, however, amounts to the same 
thing, — that the same characters or powers fit the 
plant to live better in conditions new to it than 
plants which have long lived in those conditions. 
In either case, the good comes from the fitting 
together of new characters or powers and new 
environments. Plants wliich live during many 
generations in one place become accustomed to the 
place, thoroughly fitted into its conditions, and are 
in what Mr. Spencer calls a state of equilibrium. 
When either plant or conditions change, new ad- 
justments must take place ; and the plant may find 
an opportunity to take advantage, to expand in 
some direction in which it has before been held 
back ; for plants always possess greater power 
than they are able to express. " These rhythmical 
actions or functions [of the organism]," writes 
Spencer, " and the various compound rhythms 
resulting from their combinations, are in such 
adjustment as to balance the actions to which 
the organism is subject. There is a constant or 
periodic genesis of forces which, in their kinds, 
amounts, and directions, suffice to antagonize the 
forces which the organism has constantly or peri- 
odically to bear. If, then, there exists this state 



62 PHILOSOPHY OF CROSSING PLANTS. 

of moving equilibrium among a definite set of 
internal actions, exposed to a definite set of ex- 
ternal actions, what must result if any of the 
external actions are changed ? Of course there is 
no longer an equilibrium. Some force which the 
organism habitually generates is too great or too 
small to balance some incident force ; and there 
arises a residuary force exerted by tlie environ- 
ment on the organism, or by the organism on the 
environment. This residuary force, this unbal- 
anced force, of necessity expends itself in produc- 
ing some change of state in the organism." 

The good results, therefore, are processes of 
adaptation, and when adaptation is perfectly com- 
plete the plant may have gained no permanent 
advantage over its former condition, and new 
crossing or another change may be necessar}^ ; yet 
there is often a permanent gain, as when a plant 
becomes visibly modified by change to another cli- 
mate. Now, tliis adaptive change may express 
itself in two ways : either by some direct influence 
upon the stature, vigor, or other general character, 
or indirectly upon the reproductive powers, by 
which some new influence is carried to the off- 
spring. If the direct influences become heredi- 
tary, as observation seems to show may sometimes 
occur, the two directions of modification may 
amount, ultimately, to the same thing. 

For the purposes of this discussion it is enough 



CHANGE or STOCK AND CROSSING. 68 

to know that crossing within the variety and 
change of stock within ordinary bounds are bene- 
ficial, that the results in the two cases seem to 
flow from essentially the same causes, and that 
crossing and change of stock combined give much 
better results than either one alone ; and this 
benefit is expressed more in increased yield and 
vigor than in novel and striking variations. These 
processes are much more important than any mere 
groping after new varieties, as I have already said; 
not only because they are surer, but because they 
are universal and necessary means of maintaining 
and improving both wild and cultivated plants. 
Even after one succeeds in securing and fixing 
a new variety, he must employ these means to a 
greater or less extent to maintain fertility and 
vigor, and to keep the variety true to its type. 
In the case of some garden crops, in which many 
seeds are j)^'<^cluced in each fruit and in which 
the operation of pollination is easy, actual hand- 
crossing from new stock now and then may be 
found to be profitable. But in most cases the 
operation can be left to nature, if the new^ stock 
is planted among the old. Upon this point Dar- 
win expressed himself as follows : " It is a common 
practice with horticulturists to obtain seeds from 
another place having a ver^ different soil, so as to 
avoid raising plants for a long succession of gen- 
erations under the same conditions ; but with all 



64 PHILOSOPHY OF CROSSING PLANTS. 

the species which freely intercross by the aid of 
insects or the wind, it woukl be an incomparably 
better plan to obtain seeds of the required variety, 
which had been raised for some generations under 
as different conditions as possible, and sow them 
in alternate rows with seeds matured in the old 
garden. The two stocks would then intercross, 
with a thorough blending of their whole organi- 
zations, and with no loss of purity to the variety, 
and this would yield far more favorable results 
than a mere change of seed." 

c. The Outright Production of Neiv Varneties. 

But you are waiting for a discussion of the 
second of the great features of crossing, — the sum- 
mary production of new varieties. This is the sub- 
ject which is almost universally associated with 
crossing in the popular mind, and even among 
horticulturists themselves. It is the commonest 
notion that the desirable characters of given 
parents can be definitely combined in a pronounced 
cross or hybrid. There are two or three philo- 
sophical reasons which somewhat oppose this doc- 
trine, and which we will do well to consider at the 
outset. In the first place, nature is opposed to 
hybrids, for species have been bred away from each 
other in the ability to cross. If, therefore, there 
is no advantage for nature to hybridize, Ave may 



PKODUCTION OF NOVELTIES. 65 

suppose that there would be little advantage for 
man to do so; and there would be no advantage 
for man did he not place the plant under conditions 
different from nature, or desire a different set of 
characters. We have seen that nature's chief 
barriers to hybridization are total refusal of species 
to unite, and entire or comparative seedlessness 
of offspring. We can overcome the refusal to 
cross in many cases by bringing the plant under 
cultivation ; for the character of the species be- 
comes so changed by the wholly new conditions 
that its former antipathies may be overpowered. 
Yet it is doubtful if such a plant will ever acquire 
a complete willingness to cross. In like manner 
we can overcome in a measure the comparative 
seedlessness of hybrids, but it is yevy doubtful if 
we can ever make such hybrids completely fruit- 
ful. It would appear, therefore, upon theoretical 
grounds, that in plants in which seeds are the parts 
sought, no good can be expected, as a rule, from 
hybridization ; and this seems to be affirmed by 
facts.^ 

It is evident that species which have been 
differentiated or bred away from each other in 
a given locality will have more opposed qualities 
or powers than similar species which have arisen 
quite independently in places remote from each 

1 See definition of hybrids, crosses, and other terms in the 
Glossary. 



66 PHILOSOPHY OF CROSSING PLANTS. 

other. In the one case the species have likely 
struggled with each other until each one has at- 
tained to a degree of divergence which allows it 
to persist ; while in the other case there has been 
no struggle between the species, but similar con- 
ditions have brought about similar results. These 
similar species which appear independently of 
each other in different places are called representa- 
tive species. Islands remote from each other but 
similarly situated with reference to climate very 
often contain representative species ; and the same 
may be said of other regions much like each other, 
as eastern North America and Japan. Now, it 
follows that, if representative species are less 
opposed than others, they are more likely to 
hybridize with good results ; and this fact is re- 
markably w^ell illustrated in the Kieffer and allied 
pears, which are hybrids between representative 
species of Europe and Japan ; and I am inclined 
to think that the same may be found to be true 
of the common or European apple and the wild 
crab of the Mississippi valley. Various crabs of 
the Soulard type, Avhich I once thought to con- 
stitute a distinct species, appear upon further study 
to be hybrids. We will also recall that the hybrid 
grapes which have so far proved most valuable are 
those obtained by Rogers between the American 
Vitis Labrusca and the European wine grape ; and 
that the attempts of Haskell and others to hybrid- 



INSTABILITY OF HYBRIDS. 67 

ize associated species of native grapes have given, 
at best, only indifferent results. To these good 
results from hybrids of fruit trees and vines I 
shall revert presently. 

Another theoretical point, which is borne out 
by practice, is the conclusion that, because of the 
great differences and lack of affinity between par- 
ents, pronounced hybrid offsprings are unstable. 
This is one of the greatest difficulties in the way 
of the summary production of new varieties by 
means of hybridization. It would appear, also, 
that, because of the unlikeness of parents, hj^brid 
offspring must be exceedingly variable ; but, as 
a matter of fact, in many instances the parents 
are so pronouncedly different that the hybrids 
represent a distinct type by themselves, or else 
they approach very nearly to the characters of 
one of the parents. There are, to be sure, many 
instances of exceedingly variable hybrid offspring, 
but they are usually the offspring of variable par- 
ents. In other words, variability in offspring 
appears to follow rather as a result of variability 
in parents than as a result of mere unlikeness 
of characters. But the instability of hybrid off- 
spring when propagated by seed is notorious. 
Wallace writes that " the effect of occasional 
crosses often results in a great amount of varia- 
tion, but it also leads to instability of character, 
and is therefore very little employed in the 



68 PHILOSOPHY OF CROSSING PLANTS. 

production of fixed and well-marked races." I 
may remark again that, because of the unequal 
and unknown powers of the parents, we can never 
predict what characters will appear in the hybrids. 
This fact was well expressed by Lindley a half 
century ago, in the phrase, " Hybridizing is a 
game of chance played between man and plants." 

V. Characteristics of Crosses. 

Bearing these fundamental propositions in mind, 
let us pursue the subject somewdiat in detail. 
We shall find tliat the characters of hybrids, 
as compared with the characters of simple crosses 
between stocks of the same variety, are ambiguous, 
negative, and often prejudicial. The fullest dis- 
cussion of hybrids has been made by Focke (see 
Lecture IV.), and he lays down the five following 
propositions concerning the character of hybrid 
offspring : — 

1. " All individuals which have come from the 
crossing of two pure species or races, when pro- 
duced and grown under like conditions, are 
usually exactly like each other, or at least scarcely 
more different from each other than plants of the 
same species are." This proposition, although 
perhaps true in the main, appears to be too 
broadly and positively stated. 

2. " The characters of hybrids may be different 



HYBRIDS AND CROSS-BREEDS. 69 

from the characters of the parents. The hybrids 
differ most in size and vigor and in their sexual 
powers." 

3. " Hybrids are distinguished from their par- 
ents by their powers of vegetation or growth. 
Hybrids between ver}^ different species are often 
weak, especially when young, so that it is difficult 
to raise them. On the other hand, cross-breeds 
are, as a rule, uncommonly vigorous ; they are dis- 
tinguished mostly by size, rapidity of growth, early 
flowering, productiveness, longer life, stronger 
reproductive power, unusual size of some special 
organs, and similar characteristics." 

4. " Hybrids produce a less amount of pollen 
and fewer seeds than their parents, and they 
often produce none. In cross-breeds this weaken- 
ing of the reproductive powers does not occur. 
The flowers of sterile or nearly sterile hybrids 
usually remain fresh a long time." 

5. " Malformations and odd forms are apt to 
appear in hybrids, especiall}^ in the flowers." 

Some of the relations between hybridization 
and crossing within narrow limits are stated as 
follows by Darwin : " It is an extraordinary fact 
that with many species flowers fertilized with 
their own pollen are either absolutely or in some 
degree sterile ; if fertilized with pollen from 
another flower on the same plant, they are some- 
times, though rarely, a little more fertile ; if 



70 PHILOSOPHY OF CROSSING PLANTS. 

fertilized with pollen from anotlier individual 
or variety of the same species, they are fully 
fertile ; but if with pollen from a distinct species, 
they are sterile in all possible degrees, until utter 
sterility is reached. We thus have a long series 
Avith absolute sterility at the two ends ; at one 
end due to the sexual elements not having been 
sufficiently differentiated, and at the other end 
to their having been differentiated in too great 
a degree, or in some peculiar manner." 

The difficulties in the way of successful results 
through hybridization are, therefore, these : the 
difficulty of effecting the cross ; infertility, in- 
stability, variability, and often weakness and 
monstrosity of the hybrids ; and the absolute im- 
possibility of predicting results. The advantage 
to be derived from a successful hj^bridization is 
the securing of a new variety which shall combine 
in some measure the most desirable features of 
both parents ; and this advantage is often of so 
great moment that it is worth while to make re- 
peated efforts and to overlook numerous failures. 
From these theoretical considerations it is apparent 
that h3^bridization is essentially an empirical sub- 
ject, and the results are such as fall under the 
common denomination of chance. And, as it does 
not rest upon any legitimate function in nature, 
we can understand that it will always be difficult 
to codify laws upon it. 



HYBRIDS AND BUD-PROPAGATIOX. 71 

Among the various characters of hybrid off- 
spring, I presume that the most prejudicial one is 
their instability, their tendency still to vary into 
new forms or to return to one or the other parent 
in succeeding generations. It is difficult to fix 
any particular form which we may secure in the 
first generation of hybrids. At the outset, we 
notice that this discouraging feature is manifested 
chiefly through the fact of seed-reproduction, and 
we thereby come upon what is perhaps the most 
important practical consideration in hybridization, 
— the fact that the great majority of the best 
hybrids in cultivation are increased by bud-propa- 
gation, as cuttings, layers, suckers, buds, or grafts. 
In fact, I recall very few instances in this country 
of good undoubted hybrids which are propagated 
with practical certainty by means of seeds. You 
will recall that the genera in which hybrids are 
most common are those in which bud-propagation 
is the rule ; as begonia, pelargonium, orchids, 
gladiolus, rhododendron, roses, cannas, and the 
fruits. This simply means that it is difficult to 
fix hybrids so that they will come " true to seed," 
and makes apparent the fact that if we desire 
hybrids we must expect to propagate them by 
means of buds. 

This is a point which appears to have been over- 
looked by those who contend that hybridization 
must necessarily swamp all results of natural se- 



72 PHILOSOPHY OF CKOSSING PLANTS. 

lection ; for, as comparatively few plants propagate 
habitually by means of buds, whatever hybrids 
might have appeared would have been speedily 
lost, and all the more, also, because, by the terms 
of their reasoning, the hybrids would cross with 
other and dissimilar forms, and therefore lose their 
identity as intermediates. Or, starting with the 
assumption that hybrids are intermediates, and 
would therefore obliterate specific types, we must 
conclude that they should have some marked de- 
gree of stability if they are to swamp or obliterate 
the characters of species ; but, as all hybrids tend 
to break up when propagated by seeds, it must 
follow that bud-propagation would become more 
and more common, and this is associated in nature 
with decreased seed-production. Now, seed-pro- 
duction is the legitimate function of flowers ; and 
we mast concede that, as seed-production de- 
creased, floriferousness must have decreased; and 
that, therefore, pronounced intercrossing would 
have obliterated the very organs upon which it 
depends, or have destroyed itself I 

But I may be met by the objection that there 
is no inherent reason wh}^ hybrids should not 
become stable through seed-production by in-breed- 
ing, and I might be cited to the opinion of Darwin 
and others that in-breeding tends to fix any va- 
riety, whether it originates by crossing or other 
means. And it is a fact that in-breeding tends to 



IN-BKEEDING OF CROSSES. 73 

fix varieties within certain limits, but those limits 
are often overpassed in the case of very pro- 
nounced crosses, whether cross-breeds or true 
hybrids. And if it is true, as all observation and 
experiments show, that sexual or reproductive 
powers of crosses are weakened as the cross be- 
comes more violent, Ave should expect less and less 
possibility of successful in-breeding ; for in-breed- 
ing without disastrous results is possible only with 
comparatively strong reproductive powers. As a 
matter of fact, it is found in practice that it is 
exceedingly difficult to fix pronounced hybrids by 
means of in-breeding. It sometimes happens, too, 
that the hybrid individual which we wish to per- 
petuate may be infertile with itself, as I have often 
found in the case of squashes. It is often advised 
that we cross the hybrid individual which we wish 
to fix with another like individual, or wdth one of 
its parents. These results are often successful, 
but oftener they are not. In the first place, it 
often happens that the hybrid individuals may be 
so diverse that no two of them are alike ; this has 
been my experience in many crosses. And, again, 
crossing with a parent may draw the hybrid back 
again to the parental form. So long ago as last 
century Kolreuter proved this fact upon nicotiana 
and dianthus. A hybrid between Nicotiana rus- 
tica and N. paniculata was crossed with N. pani- 
culata until it was indistinguishable from it; and 



74 PHILOSOPHY OF CROSSING PLANTS. 

it was then crossed with N. rustica until it became 
indistinguishable from that parent. Yet there is 
no other way of fixing a hybrid to be propagated 
by seeds than by in-breeding, and by constant at- 
tention to selection. Fortunatel}^, it occasionally 
happens that a hybrid is stable, and therefore 
needs no fixing. 

In this connection I may cite some of my own 
experience in crossing egg-plants and squashes ; 
for, although the products were not true hybrids 
in the strict interpretation of the Avord, many of 
them were hybrids to all intents and purposes, 
because made between very unlike varieties, and 
they will serve to illustrate the difficulties of which 
I speak. Offspring of egg-plant crosses were grown 
in 1890, and upon some of the most promising 
plants some flowers were self-pollinated. But 
these self-pollinated seeds gave just as variable 
offspring in 1891, as those selected almost at 
random from the patch ; and, what was worse, 
none of them reproduced the parent, or " came 
true to seed," and all further motive for in-breed- 
ing was gone. My labor, therefore, amounted to 
nothing more than my own edification. My 
experience in crossing pumpkins and squashes has 
now extended through many years ; and, although 
I have obtained about one thousand types not 
named or described, I have not yet succeeded in 
fixing one. The difficulty here is an aggravated 



EXPERIMENTS IN IN-BREEDING. T5 

one, however. The species are so exceedingly 
variable that all the hybrid individuals may be 
unlike, so that there can be no crossing between 
identical stocks ; and, if in-breeding is attempted, 
it may be found that the flowers will not in-breed. 
And the refusal to in-breed is all the more strange 
because the sexes are separated in different flowers 
upon the same plant. In other words, in my expe- 
rience, it is very diflicult to get good seeds from 
squashes which are fertilized by a flower upon the 
same vine. The squashes may grow normally to 
full maturity, but be entirely hollow, or contain 
only empty seeds. In some instances the seeds 
may appear to be good, but may refuse to grow 
under the best conditions. Finally, a small number 
of flowers may give good seeds. I have many 
times observed this refusal of squashes (Cucurbita 
Pepo) to in-breed. It was first brought to my 
attention through efforts to fix certain types into 
varieties. The figures of one season's tests will 
sufliciently indicate the character of the problem. 
In 1890, one hundred and eighty -five squash flowers 
were carefully pollinated with staminate flowers 
taken from the same vine which bore the pistillate 
flowers. Only twenty-two of these produced fruit, 
and of these only seven, or less than one-third, bore 
good seeds, and in some of these the seeds were 
few. Now, these twenty-two fruits represented as 
many different varieties, so that the inability to set 



76 PHILOSOPHY OF CROSSING PLANTS. 

fruit with pollen from the same vine is not a 
peculiarity of a particular variety. The records 
of the seeds of the seven fruits in 1891 are as 
follows : — 

Fruit No. 1. — Four vines were obtained, with 
four different types, two of them being white, one 
yellow, and one black. 

Fruit No. 2. — Twenty-three vines. Fifteen 
types very unlike, twelve being white and three 
yelloAv. 

Fruit No. 3. — Two vines. One type of fruit 
which was almost like one of the original parents. 

Fruit No. 4. — Thirty-two vines. Six types, 
differing cliiefly in size and shape. 

Fruit No. 5. — Twenty vines. Nineteen types, 
of which ten were white, eight orange, one striped, 
and all very unlike. 

Fruit No. 6. — Thirteen vines. Eleven types, 
— eight yellow, two black, one white. 

Fruit No. 1. — One vine. 

These offspring were jnst as variable as those 
from flowers not in-bred, and no more likely, 
apparently, to reproduce the parent. Tliese tests 
leave me Avithout any method of fixing a pro- 
nounced cross of squashes, and lead me to think 
that the legitimate process of origination of new 
kinds here, as, indeed, if not in general, is a more 
gradual process of selection, coupled, perhaps, with 
minor crossing. 



ATTEMPT TO FIX A CROSS. 77 

I will relate a definite attempt towards the fixa- 
tion of a squash which I had obtained from cross- 
ing. The history of it runs back to 1887, when a 
cross was effected between a summer yellow crook- 
neck and a white bush scallop squash. In 1889 
there appeared a squash of great excellence, com- 
bining the merits of summer and winter squashes 
with very attractive form, size, and color, and a 
good habit of plant. I showed the fruit to one of 
the most expert seedsmen of the country, and he 
pronounced it one of the most promising types 
which he had ever seen ; and, as he informed me 
that he had fixed squashes by breeding in and in, 
I was all the more anxious to carry out my own 
convictions in the same direction. It is needless 
to say that I was very happy over what I regarded 
as a great triumph. Of course I must have a large 
number of plants of my new variety, that I might 
select the best, both for in-breeding and for cross- 
ing similar types. So I selected the very finest 
squash, having placed it where I could admire it 
for some days, and saved every seed of it. These 
seeds were planted upon the most conspicuous 
knoll in my garden in 1890. It was soon evident 
that something was wrong. I seemed to have 
everj^tliing except my squash. One plant, how- 
ever, bore fruits almost like the parent, and upon 
this I began my attempts towards in-breeding. 
But flower after flower failed, and I soon saw that 



78 PHILOSOPHY OF CROSSING PLANTS. 

the plant was infertile with itself. Careful search 
revealed two or three other plants very like this 
one, and I then proceeded to make crosses upon it. 
I was equally confident that this method would 
succeed. When I harvested my squashes in the 
fall and took account of stock, I found that the 
seeds of my one squash had given just as many 
different types as there were plants, and I actually 
counted one hundred and ten kinds distinct enough 
to be named and recognized. Still confident, in 
1891 1 planted the seeds of my few crosses, and as 
the summer days grew long and the crickets 
chirped in the meadows, I watched the expanding 
squash blossoms and wondered what they would 
bring forth. But they brought only disappoint- 
ment. Not one seed produced a squash like the 
parent. My -squash had taken an unscientific 
leave of absence, and I do not know its where- 
abouts. And when the frost came and killed 
every ambitious blossom, my hope went out and 
has not yet returned! 

Let us now recall how many undoubted hybrids 
there are, named and known, among our fruits 
and vegetables. In grapes there are the most. 
There are Rogers' hybrids, like the Agawam, 
Lindley, Wilder, Salem, and Barry; and there is 
some reason for supposing that the Delaware, 
Catawba, and other varieties are of hybrid origin. 
And many hybrids have come to notice lately 



LIST OF COMMON HYBRIDS. 79 

throiiofh the work of Munson and others. But it 
must be remembered that grapes are naturally ex- 
ceedmgly variable, and the specific limits are not 
well known, and that hybridization among them 
lacks much of that definiteness which ordinarily 
attaches to the subject. In pears there is the 
Kieffer class. In apples, peaches, plums, cher- 
ries, gooseberries, and currants, there are no im- 
portant commercial hybrids. In blackberries there 
is the blackberry-dewberry class, represented by 
the Wilson Early and others. Some of the rasp- 
berries, like the Philadelphia and Shaffer, are hy- 
brids between the red and black species. Hybrids 
have been produced between the raspberry and 
blackberry by two or three persons, but they pos- 
sess no promise of economic results. Among all 
the list of garden vegetables (plants which are 
propagated by seeds) I do not know of a single 
important hybrid ; and the same is true of wheat, 
— unless the Carman wheat-r3^e varieties become 
prominent, — oats, the grasses, and other farm 
crops. But among ornamental plants there are 
many ; and it is a significant fact that the most 
numerous, most marked, and most successful hy- 
brids occur in the plants most carefully cultivated 
and protected, those, in other words, which are 
farthest removed from all untoward circumstances 
and an independent position. This is nowhere so 
well illustrated as in the case of cultivated orchids, 



80 PHILOSOPHY OF CROSSING PLANTS. 

in which hybridization has played no end of freaks, 
and in which, also, every individual plant is nursed 
and coddled.! With such plants the struggle for 
existence is reduced to its lowest terms ; for it 
must be borne in mind tliat, even in the garden, 
plants must fight severely for a chance to live, and 
even then only the very best can persist, or are 
even allowed to try. 

I am sure that this list of hybrids is much more 
meagre than most catalogues and trade-lists would 
have us believe, but I am sure that it is approxi- 
mately near the truth. It is, of course, equivalent 
to saying that most of the so-called hybrid fruits 
and vegetables are myths. There is everywhere a 
misconception of what a hybrid is, and how it 
comes to exist ; and yet, perhaps because, of this 
indefinite knowledge, there is a wide-spread feel- 
ing that a hybrid is necessarily good, while the 
presumption is directly the opposite. The identity 
of a hybrid in the popular mind rests entirely upon 
some superficial character, and proceeds upon the 
assumption that it is necessarily intermediate be- 
tween the parents. Hence we find one of our 
popular authors asserting that, because the kohl- 
rabi bears its thickened portion midway of its stem, 
it is evidently a hybrid between the cabbage and 
turnip, which bear respectively the thickened parts 

1 Consult E. Bohnhof, " Dictionnaire des Orchid^es Hy- 
brides," Paris, 1895. 



INFLUENCE OF PARENTS. 81 

at the opposite extremities of the stem I And then 
there are those who confonnd the word hybrid 
with high-hred^ and who buiki attractive castles 
upon the unconscious error. And thus is confu- 
sion confounded ! 

But, before leaving this subject of hybridization, 
I must speak of the old yet common notion that 
there is some peculiar influence exerted by each 
sex in the parentage of hybrids ; for I shall tliereby 
not only call your attention to what I believe to 
be an error, but shall also find the opportunity to 
still further illustrate the entanglements of hybri- 
dization. It was held by certain early observers, of 
whom the great Linniieus was one, that ths female 
parent determines the constitution of the hybrid, 
while the male parent gives the external attributes, 
as form, size, and color. The accumulated experi- 
ence of nearly a century and a half appears to con- 
tradict this proposition, and Focke, who has recently 
gone over the whole ground, positively declares 
that it is untrue. There are instances, to be sure, 
in which this old idea is affirmed, but there are 
others in which it is contradicted. The truth ap- 
pears to be this, — that the parent of greater 
strength or virility makes the stronger impression 
upon the hybrids, whether it is the staminate or 
pistillate parent ; and it appears to be equally 
true that it is usually impossible to determine be- 
forehand which parent is the stronger. It is cer- 



82 PHILOSOPHY OF CROSSING PLANTS. 

tain that strength does not lie in size, neither in 
the high development of any character. It appears 
to be more particularly associated with \Yhat we 
call fixity or stability of character, or the tendency 
towards invariability. 

This has been well illustrated in my own experi- 
ments with squashes, gourds, and pumpkins. The 
common little pear-shaped gourd will impress itself 
more strongly upon crosses than any of the edible 
squashes and pumpkins with which it will effect a 
cross, whether it is used as male or female parent. 
Even the imposing and ubiquitous great field 
pumpkin, which every New Englander associates 
with pies, is overpowered b}^ the little gourd. 
Seeds from a large and sleek pumpkin which had 
been fertilized by gourd pollen, produced gourds 
and small hard-shelled globular fruits which were 
entirely inedible. A more interesting experiment 
was made between the handsome green-stri^Dcd Ber- 
gen fall squash and the little pear gourd. Several 
flowers of the gourd were pollinated b}^ the Bergen 
in 1889. The fruits raised from these seeds in 
1890 were remarkably gourd-like. Some of these 
crosses were pollinated again in 1890 by the Ber- 
gen, and the seeds were sown in 1891. Here, 
then, were crosses into which the gourd had gone 
once and the Bergen twice, and both the parents 
are to all appearances equally fixed, the difference 
in strength, if any, attaching rather to the Bergen. 



POLLINATION IS UNCERTAIN. 83 

Now, the crop of 1891 still carried pronounced 
characters of the gourd. Even in the fruits which 
most resembled the Bergen, the shells were almost 
flinty hard, and the flesh, even when thick and 
tender, was bitter. Some of the fruits looked so 
much like the Bero^en that I was led to think that 
the gourd had largely disappeared. The very hard 
but thin paper-like shell which the gourd had laid 
over the thick yellow flesh of the Bergen, I 
thought might serve a useful purpose, and make 
the squash a better keeper. And I found that it 
was a great protection, for the squash could stand 
any amount of rough handling, and was even not 
injured by ten degrees of frost. All this was an 
acquisition, and, as the squash was handsome and 
exceedingly productive, nothing more seemed to 
be desired. But it still remained to have a squash 
for dinner. The cook complained of the hard 
shell, but, once inside, the flesh was thick and 
attractive, and it cooked nicely. But the flavor ! 
Dregs of quinine, gall, and boneset! The gourd 
was still there ! 

yj. Uncertainties of Pollination. 

We have now seen that uncertainty follows 
hybridization, and, in closing, I Avill say that 
uncertainty also attaches to the mere act of 
pollination. Between some species which are 



84 PHILOSOPHY OF CROSSING PLANTS. 

closely allied and which have large and strong 
flowers, four-fifths of the attempts towards cross- 
pollination may be successful ; but such a large 
proportion of successes is not common, and it 
may be infrequent even in pollinations between 
plants of the same species or variety. Some of 
the failure is due in many cases to unskilful opera- 
tion, but even the most expert operators fail as 
often as they succeed in promiscuous pollinating. 
There is good reason to believe, as Darwin has 
shown, that the failure may be due to some selec- 
tive power of individual plants, by which they re- 
fuse pollen which is, in many instances, acceptable 
to other plants even of the same variety or stock. 
The lesson to be drawn from these facts is that 
operations should be as many as possible, and that 
discouragement should not come from failure. 
In order to illustrate the varying fortunes of the 
pollinator, I will transcribe some notes from my 
field-book. 

Two hundred and thirty-four pollinations of 
gourds, pumpkins, and squashes, mostly between 
varieties of one species (Cucurbita Pepo), and in- 
cluding some individual pollinations, gave one 
hundred and seventeen failures and one hundred 
and seventeen successes. These crosses were made 
in varying weather, from July 28 to August 30. 
In some periods- nearly all the operations would 
succeed, and at other times most of them would 



RECOIIDS OF POLLINATIONS. 85 

fail. I have always regarded these experiments as 
among my most successful ones, and yet but half 
of the pollinations " took." But one must not 
understand that I actuall}^ secured seeds from even 
all these one hundred and seventeen fruits, for 
some of them turned out to be seedless, and some 
were destroyed by insects before they were ripe, or 
they were lost by accidental means. A few more 
than half of the successful pollinations — if by suc- 
cess we mean the formation and growth of fruit — 
really secured us seeds, or about one-fourth of the 
whole number of efforts. 

Twenty pollinations were made between potato 
flowers, and they all failed ; also, seven pollinations 
of red peppers, four of husk-tomato, two of Nico- 
tiana affinis upon petunia and. two of the reciprocal 
cross, twelve of radish, one of Mirabilis Jalapa upon 
M. longiflora and two of the reciprocal cross, three 
Convolvulus major upon C. minor and one of the 
reciprocal, one muskmelon by squash, two musk- 
melons by watermelon, and one muskmelon by 
cucumber. 

This is but one record. Let me give another : — 
Cucumber, ninety-five efforts : lifty-two suc- 
cesses, forty-three failures. Tomato, forty-three 
efforts: nineteen successes, twenty-four failures. 
Egg-plant, seven efforts : one success, six failures. 
Pepper, fifteen efforts : one success, fourteen fail- 
ures. Husk-tomato, forty-five efforts : forty-five 



86 PHILOSOPHY OF CROSSIKG PLANTS. 

failures. Pepiiio, twelve efforts : twelve failures. 
Petunia by Nicotiana affinis, eleven efforts : eleven 
failures. Nicotiana affinis bj petunia, six efforts : 
six failures. General Grant tobacco by Nicotiana 
affinis, eleven efforts : eight successes, three fail- 
ures. Nicotiana affinis by General Grant tobacco, 
fifteen efforts : fifteen failures. General Grant 
tobacco by General Grant tobacco, one effort : one 
success. Nicotiana affinis b}^ Nicotiana affinis, three 
efforts : two successes, one failure. Tuberous be- 
gonia, five efforts : five successes. 

Total, three hundred and twelve efforts : eighty- 
nine successes, two hundred and twenty-three 
failures. 

Conclusion. 

And now, the sum of it all is this : encourage in 
every way crosses within the limits of the variety 
and in connection with change of stock, expecting 
increase in vigor and productiveness ; hybridize 
if you wish to experiment, but do it carefully, 
sj'Stematically, thoroughly, and do not expect too 
much. Extend Darwin's famous proposition to 
read : Nature abhors both perpetual self-fertiliza- 
tion and hybridization. 



LECTURE III. 

HOW DOMESTIC VARIETIES ORIGINATE. 

"The key is man's power of accumulative 
selection : nature gives successive variations ; 
man adds them up in certain directions useful 
to liim." This, in Darwin's phrase, is the essence 
of the cultivator's skill in ameliorating the vege- 
table kingdom. So far as man is concerned, the 
origin of the initial variation is largely chance, 
but this start or variation once given, he has the 
power, in most cases, to perpetuate it and to 
modify its characters. There are, then, two very 
different factors or problems in the origination of 
garden varieties, — the production of the first de- 
parture or variation, and the subsequent breeding 
of it. Persons who give little thought to the sub- 
ject, look upon variation as the end of their endeav- 
ors, thinking that a form comes into being with all 
its characters Avell marked and fixed. In reality, 
however, variation is but the beginning ; selection 
is the end. 

I. Indeterminate Varieties. 

There are two general classes of garden varie- 
ties as respects the method of their origin, — 

87 



88 HOW DOMESTIC VAEIETIES ORIGINATE. 

those wliicli come into existence somewhat sud- 
denly and which require little else of the hus- 
bandman than the multij)lication of them, and 
those which are the result of a slow evolution or 
direct breeding. The former are indeterminate 
or uncertain, and the latter are determinate or 
definite. The greater part of those in the first 
class are plants which are multiplied or divided 
by bud-propagation. They comprise nearly all 
our fruits, the woody ornamental plants, and such 
herbaceous genera as begonia, canna, gladiolus, 
lily, dahlia, carnation, chrysanthemum, and the 
like, — in fact, all those multiplied by grafting, 
cuttings, bulbs, or other asexual parts. The 
original plant may be either a seedling or a bud- 
sport. The gardener, who is always on the look- 
out for novelties, discovers its good qualities and 
propagates it. 

Varieties which are habitually multiplied by 
buds, as in those plants which I have mentioned 
in the last paragraph, vary widely when grown 
from seeds, so that every seedling may be 
markedly distinct. As soon, however, as varie- 
ties are widely and exclusively propagated by 
seeds, they develop a capacity of carrying the 
greater part of the individual differences down 
to the offspring. That is, seedlings from bud- 
multiplied plants do not " come true," as a rule, 
whilst those from seed -propagated plants do 



INDETERMINATE VAIIIETIES. 89 

"come true." The reason of tliis difference Avill 
become apparent upon a moment's reflection. In 
the seed-propagated plants, like the kitchen-gar- 
den vegetables and the annual flowers, we select 
the seeds and thereby eliminate all those varia- 
tions which would have arisen had the discarded 
seeds been sown. In other Avords, we are con- 
stantly fixing the tendency to " come true," for 
this feature of plants is as much a variation as 
form or color or any other attribute is. Suppose, 
for instance, that a certain variation were to re- 
ceive two opposite treatments, the seeds from one- 
half of the progeny being carefully selected year 
by year, and all those from untypical plants dis- 
carded, whilst in the other half all the seeds from 
all the plants, whether good or bad, are saved 
and sown. In the one case, it will be seen, we 
are fixing the tendency to " come true," for this 
is all that constitutes a horticultural variety, — 
a brood wliich is very much like all its parents. 
In the other case, we are constantly eliminating 
the tendency to "come true" by alloAving every 
modifying agency full sway. So the very act of 
taking seeds only from plants which have " come 
true," tends to still more strongly fix the heredi- 
tary force within narrow limits. Working against 
this restrictive force, however, are all the agencies 
of environment, so that, fortunately, now and 
then a seed gives a "rogue," or a plant Avidely 



90 HOW DOMESTIC VARIETIES ORIGINATE. 

unlike its parent, and this may be the start for a 
new variety. 

With bud-multiplied varieties, however, the 
case is very different. Here every seed may be 
sown, as in the illustrative case above, because 
the seedlings are not wanted for themselves, but 
simply as stocks upon which to bud or graft the 
desired varieties. So there is no seed selection in 
the ordinary propagation of apples, pears, peaches, 
and the other orchard fruits. The seeds are taken 
indiscriminately from pomace or the refuse of can- 
ning and evaporating factories. But every annual 
garden vegetable is always grown from seeds more 
or less carefull}^ saved from plants which possess 
some desired attribute. There is no reason why 
the tree fruits should not reproduce themselves 
from seeds just as closely as the annual herbs do, if 
they were to be as carefully propagated by selected 
seeds through a long course of generations. There 
is excellent proof of this in the well-marked races 
or families of Russian apples. In that country, 
grafting has been little employed, and conse- 
quently it has been necessary to select seeds 
only from acceptable trees in order that the off- 
spring might be more acceptable. So the Russian 
apples have come to run in groups or families, each 
family bearing the mark of some strong ancestor. 
Most of the seedlings of the Duchess of Olden- 
burg are recognizable because of their likeness to 



PLANT-BKEEDING. 



91 



the parent. We may tlius trace an incipient ten- 
dency in our own fruits towards racial characters. 
The Fameuse type of apples, for example, tends to 
perpetuate itself ; and a similar tendency is very 
well marked in the Damson and Green Gage 
plums, the Orange quince. Concord grape, and 
Hill's Chili and Crawford peaches. But inas- 
much as bud-multiplication is so essential in 
nursery practice, we can hardly hope for the 
time when our trees and shrubs, or even our per- 
ennial herbs, will ''come true" with much cer- 
tainty. In them, therefore, we get new varieties 
by simply sowing the seeds; but in seed-propa- 
gated varieties we must depend either upon cliance 
variations or else we must resort to definite plant- 
breedhig. 

II. Plant-breeding. 

The breeding of domestic animals is attended, 
for the most part, with such definite and often 
precise results that there has come to be a gen- 
eral desire to extend the same principles to 
plants. It is not unusual to hear well-informed 
people say that it is possible to breed plants with 
as much certainty and exactness as it is to breed 
animals. The fact is, however, that such exact- 
ness will never be possible, because plants are 
very unlike animals in organization, and because, 



92 HO^Y DOMESTIC VARIETIES ORIGINATE. 

also, the objects sought in the tAvo cases are fun- 
damentally unlike. Plants, as we have seen, are 
made up of a colony of potential individuals, and 
to breed between tAvo plants by crossing means 
that we must choose the sex-parents from amongst 
as many indi\^iduals as there are flowers or branches 
on the two plants, whilst in animals we choose two 
definite personal parents. And these personal 
parents are either male or female, and the union 
is essential to the production of offspring, whilst 
in plants each parent — that is, each flower — is 
generally both male and female, and the union of 
two is not essential to the production of offspring, 
for the plant is capable of multiplying itself by 
buds. The element of chance, therefore, is one 
hundred, or more, to one in crossing plants as 
compared with crossing animals. Then, again, 
the plant-parents are modified profoundly by every 
environmental condition of soil and temperature 
and sunshine, or other external condition, since 
they possess no bodily temperature, no choice of 
conditions, and no volition to enable them to 
overcome the circumstances in which they are 
placed. Animals, on the contrary, have all these 
elements of personality, and the breeder is also 
able to control the conditions of their lives to a 
nicety. In view of all these facts, it is not strange 
that animals can be bred by crossing with more 
confidence than plants can. But there is another 



ANIMALS AND PLANTS. 93 

and even more important difference between the 
breeding of animals and tlie breeding of plants. 
In animals, our sole object is to secure simply one 
animal or one brood of offspring. In plants, our 
object is, in general, to secure a race or genera- 
tions of offspring, which may be disseminated 
freely over the earth. In the bovine race, for 
example, our object in breeding is to produce one 
cow with given characters ; in turnips, our object 
is to produce a ncAV variety, the seed of which 
will reproduce the variety, whether sown in Penn- 
sylvania or Ceylon. It is apparent, therefore, that 
any comparisons drawn between the breeding of 
animals and plants are fundamentally fallacious. 

Is there, then, any such thing as plant-breeding, 
any possibility that the operator can proceed with 
some confidence that he may obtain the ideal 
which he has in mind ? Yes, to a certain extent. 

It is apparent that the very first effort on the 
part of the plant-breeder must be to secure indi- 
vidual differences ; for so long as the plants which 
he handles are very closely alike, so long there 
will be little hope of obtaining new varieties. He 
must, therefore, cause his plants to vary. In 
plants which are comparatively unvariable, it is 
frequently impossible to produce variations in the 
desired direction at once, but it is more important 
to "break " the type, — that is, to make it depart 
markedly from its normal behavior in any or 



94 HOW DOMESTIC VARIETIES ORIGINATE. 

many directions (page 19). If the type once 
begins to vary, to break up into different forms, 
the operator may be sure that it will soon become 
plastic enough to alloAV of modification in the 
manner which he desires. But whilst it is im- 
portant or even necessary to break a well-marked 
type into many forms, it Avould no doubt be un- 
wise to encourage this tendency after it once 
appears, lest the plant acquire a too strong habit 
of scattering. This initial variation is induced 
by changing the conditions in which the plant has 
habitually grown, as a change of seed, change of 
soil, tillage, varying the food supply, crossing and 
the like. 

As a matter of fact, however, nearly all plants 
which have been long cultivated are already suf- 
ficiently variable to afford a starting-point for 
breeding. The operator should have a vivid 
mental picture of the variety which he designs to 
obtain ; then he should select that plant in his 
plantation Avhich is the nearest his ideal, and sow 
the seeds of it. From the seedlings he should 
again select the individuals which most nearly 
approach his type, and so on, generation after 
generation, until the desired object is attained. 
It is important, if he is to make rapid progress, 
that he keep the same ideal in mind year by year, 
otherwise there Avill be vacillation and the prog- 
ress of one year may be undone by a counter 



ANTAGONISTIC FEATURES. 95 

movement the following year. In this way, it 
will be found that almost any character of a plant 
may be either intensified or lessened. This is 
man's nearest approach to the Creator in his 
dominion over the physical forms of life, and it 
is great and potent in proportion as it sets for 
itself correct ideals in the beginning and adheres 
to them until the end. 

When beginning this selection or breeding for 
an ideal, it is important that impossible or contra- 
dictory results should be avoided. Some of the 
cautions and suggestions which need to be con- 
sidered are these : — 

1. Avoid striving after features which are antag- 
onistic or foreign to the species or genus with ivhich 
you are tvorking. Every group of plants has be- 
come endowed with certain characters or lines 
of develojDment, and the cultivator will secure 
quicker and surer results if he works along the 
same lines, rather than to attempt to thwart them. 
Nature gives the hint : let men follow it out, 
rather than to endeavor to create new types of 
characters. Let us take some of the solanaceous 
plants as examples. There are certain types of 
the genus solanum which have a natural habit of 
tuber-bearing, as the potato. Such species should 
be bred for tubers and not for fruits. There are 
other solanum s, however, like the egg-plants and 
the pepinoes, wdiich naturally vary or develop in 



96 HOW DOMESTIC VARIETIES ORIGINATE. 

the direction of fruit-bearing, and these shouki be 
bred for fruits and not for tubers ; and the same 
should be true in the related genera of tomatoes, 
red peppers, and physalis. Those ambitious per- 
sons who are always looking for a tuber-bearing 
tomato, therefore, might better concentrate their 
energies on the potato, for the tomato is not devel- 
oping in that direction ; and even if the tomato 
could be made to produce tubers, it would thereby 
lessen its fruit production, for plants cannot main- 
tain two diverse and profitable crops at the same 
time. It is more reasonable, and certainly more 
practicable, to grow potatoes on potato plants and 
tomatoes on tomato plants. 

2. The quichest and most marked residts are to 
he expected in those groups or species which are nor- 
mally the most variable. There are a greater num- 
ber of variations or starting-points in such species ; 
but it also follows that the forms are less stable 
the more the species is variable. Yet the varia- 
tions, being very plastic, yield themselves readily 
to the wishes of the operator. Carriere puts the 
thought in this form : " The stability of forms, in 
any group of plants, is, in general, in inverse ratio 
to the number of the species which it contains, 
and also to the degree of its domestication." 

The most variable types are the most dominant 
ones over the earth ; that is, they occur in greater 
numbers and under more diverse conditions than 



VAKIABLE TYPES. 97 



the comparatively invariable types do. The com- 
positce, or sunflower-like plants, comprise a nmth 
or tenth of the total species of flowering plants, 
and the larger part of the subordinate types or 
genera contain many forms or species. Aster, 
goldenrod, the hawkweeds, thistles, and other 
groups, are representative of the cosmopolitan or 
variable types of composites. Whenever, for any 
reason, anv type begins to decline in variability, 
it also begins to perish ; it is then tending towards 
extinction. Monotypic genera-those which con- 
tain but a single species -are generally of local 
or disconnected distribution, and are, for tlie most 
part, vanishing remnants of a once dommant or 
important type. As a rule, most of our widely 
variable and staple cultivated species are mem- 
bers of large, or at least polytypic genera, buch, 
for example, are the apples and pears, peaches 
and plums, oranges and lemons, roses, bananas, 
chrysanthemums, pinks, cucurbits, beans, potato, 
grapes, barley, rice, cotton. A marked exception 
to this statement is maize, which is immensely 
variable and is generally held to have come from 
a single species ; but the genesis of maize is un- 
known, and it is possible, though scarcely proba- 
ble, that more than one species is concerned in it. 
Wheat is also a partial exception, although the 
original specific type is not understood ; and the 
latest monographers admit three or four other spe- 



H 



98 HOW DOMESTIC VARIETIES ORIGINATE. 

cies to the genus, aside from wheat. There are 
other exceptions, but they are mostly unimportant, 
and, in the main, it may be said that the domi- 
nant domestic types of plants represent markedly 
l^olytypic genera. 

3. Breed for one thing at a time. The person 
who strives at the same time for increase or modi- 
fication in prolificacy and flavor will be likely to 
fail in both. He should work for one object 
alone, simply giving sufficient attention to sub- 
sidiary objects to keep them up to normal stand- 
ard. This is really equivalent to saying that 
there can be no such thing as the perfect all- 
around variety which so many people covet. Va- 
rieties must be adapted to specific uses, — one for 
shipping, one for canning, one for dessert, one for 
keeping qualities, and the like. The more good 
varieties there are of any sj^ecies, the more widely 
and successfully that species can be cultivated. 

4. Do not desire contradictory attributes in any 
variety. A variety, for example, which bears the 
maximum number of fruits or flowers cannot be 
expected to greatly increase the size of those 
organs without loss in number^. This is well 
shown in the tomato. The original tomato pro- 
duced from six to ten fruits in a cluster, but as 
the fruits increased in size the numbers in each 
cluster fell to two or three. That is, increase in 
size proceeded somewhat at the expense of numer- 



SELECT FOR THE ENTIRE PLANT. 99 

ical productivity ; yet the total weight of fruit 
per plaut has greatly increased. The same is 
true of apples and pears ; for whilst these trees 
bear flowers in clusters, they generall}^ bear their 
fruits singly. Originally, every flower normally 
set fruit. The reason why blackberries, currants, 
and grapes do not increase more markedly in size, 
is probably because the size of cluster has been 
given greater attention than the size of berry. 
Plants which now bear a full crop of tubers 
cannot be expected to increase greatly in fruit- 
bearing, as I have already explained under 
Rule 1. This fact is illustrated in the potato, 
in which, as tuber production has increased, seed 
production has decreased, so that potato growers 
now complain that potatoes do not produce bolls 
as freely as they did years ago. 

5. When selecting seeds, remember that the char- 
acter of the luhole plant is more important than the 
character of any one branch or part of the plant ; 
and the more uniform the plant in all its parts, the 
greater is the likelihood that it will transmit its 
characters. If one is striving for larger floAvers, 
for instance, he will secure better results if he 
choose seeds from plants which bear large flowers 
throughout, than he will if he choose them from 
some one large-flowering branch on a plant which 
bears indifferent flowers on the remaining branches, 
even though this given branch produce much larger 



100 HOW DOMESTIC VARIETIES ORIGINATE. 

flowers than those borne on the large -flowered 
plant. Small potatoes from productive hills give 
a better product than large potatoes from unpro- 
ductive hills. The practice of selecting large 
ears from a bin of corn, or large melons from the 
grocer's wagon, is much less efficient in produc- 
ing large products the following season than the 
practice of going into the fields and selecting the 
most uniformly large-fruited parents would be. 
A very poor plant may occasionally produce one 
or two very superior fruits, but the seeds are 
more likely to perpetuate the characters of the 
plant than of the fruits. 

The following experiences detailed by Henri L. 
de Vilmorin illustrate my proposition admirably: 
" I tried an experiment with seeds of Chrysanthe- 
mum carinatum gathered on double, single, and 
semi-double heads, all growing on one plant, 
and found no difference wdiatever in the propor- 
tion of single and double-flowered plants. In 
striped verbenas, an unequal distribution of the 
color is often noticed ; some heads are pure white, 
some of a self color, and most are marked with 
colored stripes on white ground. I had seeds 
taken severally from all and tested alongside 
one another. The result was the same. All the 
seeds from one plant, whatever the color of the 
flower that bore them, gave the same proportion 
of plain and variegated flowers." 



UNIFORMNESS IN THE PARTS. 101 

The second part of my proposition is equally as 
important as the first, — the fact that a plant 
which is uniform in all its branches or parts is 
more likely to transmit its general features than 
one which varies within itself. It is well known 
that bean plants often produce beans with various 
styles of markings on the same plant or even in 
the same pod, yet these variations rarely ever 
perpetuate themselves. The same remark may 
be applied to variations in peas. These illustra- 
tions only add emphasis to the fact that intending 
plant-breeders should give greater heed than they 
usually do to the entire plant, rather than confine 
their attention to the particular part or organ 
which they desire to improve. 

At first thought, it may look as if these facts 
are directly opposed to the proposition which I 
emphasized in my first lecture, that every branch 
of a plant is a potential autonomy, but it is really 
a confirmation of it. The variation itself shows 
that the branch is measurably independent, but it 
is not until the conditions or causes of the vari- 
ation are poAverful enough to affect the entire 
plant that they are sufficiently impressed upon 
the organization of the plant to make their effects 
hereditfiry. 

There is an apparent exception to the law that 
the character of the entire plant is more impor- 
tant than any one organ or part of it, in the case 



102 HOW DOMESTIC VARIETIES ORIGINATE. 

of the seeds themselves. That is, better results 
usually follow the sowing of large and heavy 
seeds than of small or unselected seeds from the 
same plant. This, however, does not affect the 
main proposition, for tlie seed is in a measure 
independent of the plant -body, and is not so 
directly influenced by environment as the other 
organs are. And, again, the seed receives a part 
of its elements from a second or male parent. 
The good results which follow the use of large 
seeds are, chiefly, greater uniformity of crop, 
increased vigor, often a gain in earliness and 
sometimes in bulk, and generally a greater ca- 
pacity for the production of seeds. These results 
are probably associated less with any innate he- 
reditable tendencies than with the mere vegeta- 
tive strength and uniformness of the large seeds. 
The large seeds usually germinate more quickly 
than the small ones, provided both are equally 
mature, and they push the plantlet on more 
vigorously. This initial gain, coming at the 
most critical time in the life of the new indi- 
vidual, is no doubt responsible for very much of 
the result which follows. The uniformity of crop 
is the most important advantage which comes of 
the use of large seeds, and this is obviously the 
result of the elimination of all seeds of varying 
degrees of maturity, of incomplete growth and 
formation, and of low vitality. 



PROGENY OF IMMATURE SEEDS 103 

Another important consideration touching the 
selection of seeds is the fact that very immature 
seeds give a feeble but precocious progeny. This 
has long been observed by gardeners, but Sturte- 
vant, Arthur, and Goff have recently made a 
critical examination of the subject. " It is not 
the slightly unripe seeds that give a noticeable 
increase in earliness," according to Arthur, " but 
very unripe seeds, gathered from fruit [tomatoes] 
scarcely of full size and still very green. Such 
seeds do not weigh more than two-thirds as much 
as those fully ripe. They germinate readily, but 
the plantlets lack constitutional vigor and are 
more easily affected by retarding or harmful 
influences. If they can be brought through the 
early period of growth and become well estab- 
lished, and the foliage or fruit is not attacked by 
rots or blights, the grower will usually be re- 
warded by an earlier and more abundant crop of 
slightly smaller and less firm fruit. These char- 
acters will be more strongly emphasized in sub- 
sequent years by continuous seed propagation." 
Goff remarks that the increase in earliness in 
tomatoes, following the use of markedly immature 
seeds, '' is accompanied by a marked decrease in 
the vigor of the plant, and in the size, firmness, 
and keeping quality of the fruit." These results 
are probably closely associated with the chemical 
constitution and content of the immature seeds. 



104 HOAV DOMESTIC VARIETIES ORIGINATE. 

The organic compounds have probably not yet 
reached a state of stability, and they therefore 
respond quickly to external stimuli when placed 
in conditions suitable to germination ; and there 
is little food for the nourishment of the plantlet. 
The consequent weakness of the plantlet results 
in a loss of vegetative vigor, which is earliness 
(see Rule 11). 

Still another feature connected with the choice 
of seeds is the fact that in some plants, as in some 
Ipomoeas, for example, the color of the seed is 
more or less intimately associated with the color 
of the flower which produced them and also with 
the color of the flowers which they will produce. 

6. Plants which have any desired characteristics 
in common may differ widely in their ability to 
transmit these characters. It is generally impos- 
sible for the cultivator to determine, from the 
appearance of any given number of similar plants, 
which of them will give progeny the most unvari- 
able and the most like its parent ; but it may be 
said that those individuals which grow in the most 
usual or normal environments are most likely to 
perpetuate themselves. A very unusual condi- 
tion, as of soil, moisture, or exposure, is not easily 
imitated when providing for the succeeding gen- 
eration, and a return to normal conditions of envi- 
ronment may be expected to be followed by a more 
or less complete return to normal attributes on the 



SELECT SEVERAL STARTING-POINTS. 105 

part of the plant. If the same variation, there- 
fore, were to occur in plants growing under widely 
different conditions, the operator who wishes to 
preserve the new form sliould take particular care 
to select his seeds from those individuals which 
seem to have been least influenced by the imme- 
diate conditions in which they have grown. 

Again, if the same variation appears both in 
uncrossed and crossed plants, the best results 
should be expected in selecting seeds from the 
former. We have already seen, in the second 
lecture, how it is that crosses are unstable, and 
how the instability is apt to be the greater the 
more violent the cross. " Cross-breeding greatly 
increases the chance of wide variation," writes 
Henri L. de Yilmorin, " but it makes the task of 
fixation more difficult." 

It is very important, therefore, when selecting 
seeds from plants which seem to give promise of 
a new variety, to sow the seeds of each plant 
separately, and then make the subsequent selec- 
tions from the most stable generation ; and it is 
equally important that the operator should not 
trust to a single plant as a starting-point, when- 
ever he has several promising plants from which 
to choose. 

7. TJie less marked the dei^arture from the 
genius of the normal type^ the greater^ in general^ 
is the likelihood that it tvill he perpetuated. That 



106 HOW DOMESTIC VARIETIES ORIGINATE. 

is, widely aberrant forms are generally unstable. 
This is admirably illustrated in crosses. The 
seed-progeny of crosses between closely related 
varieties, or between different plants of the same 
variety, is more uniform and generally more easy 
of improvement by selection than the progeny of 
hybrids. In uncrossed plants, the general ten- 
dency is to resemble their parents, and the greater 
the number of like ancestors, the greater is the ten- 
dency to "come true." There is thought to be a 
tendency, though necessarily a weak one, to return 
to some particular ancestor, or to ''date back." 
This is known as atavism. The so-called atavistic 
forms are likely to be unstable, to break up into nu- 
merous forms, or to return more or less completely 
to the type of the main line of the ancestry. The 
following statements touching some of the rela- 
tions of atavism to the amelioration of plants, are 
the results of an excellent study of heredity in 
lupines by Louis Leveque de Vilmorin : — 

"1. The tendency to resemble its parents is 
generally the strongest tendency in any plant; 

"2. But it is notably impaired as it comes 
into conflict with the tendency to resemble the 
general line of its ancestry. 

" 3. This latter tendency, or atavism, is con- 
stant, though not strong, and scarcely becomes 
impaired by the intervention of a series of gen- 
erations in which no reversion has taken place. 



CROSSING NOT AN END. 107 

"4. The tendency to resemble a near pro- 
genitor (only two or three generations removed), 
on the other hand, is very soon obliterated if the 
given progenitor is different from the bulk of 
its ancestors." 

8. The crossing of plants should be looked upon 
as a means or starting-point., not as an end. We 
cross two flowers and sow the seeds. The result- 
ing seedlings may be unlike either parent. Here, 
then, is variation. The operator should select 
that plant which most nearly satisfies his ideal, 
and then, by selection from its progeny and the 
progeny of succeeding generations, gradually ob- 
tain the plant which he desires. It is only in 
plants which are propagated by asexual j^arts — as 
grafts, cuttings, layers, bulbs, and the like — that 
hybrids or crosses are commonly immediately val- 
uable; for in these plants we really cut up and 
multiply the one individual plant which pleases us 
in the first batch of seedlings, rather than to take 
the offspring or seedlings of it. Thus, if any 
particular plant in a lot of seedlings of crosses 
of cannas, or plums, or hops, or straAvberries, or 
potatoes, is valuable, we multiply that one in- 
dividual. There is no occasion for fixing the 
variety. But any satisfactory plant in a lot of seed- 
lings of crosses of pumpkins, or wheat, or beans, 
must be made the parent of a new variety by sow- 
ing the seeds of it and then by selecting for seed- 



108 HOW DOMESTIC VARIETIES ORIGINATE. 

parents, year by year, tliose plants Avliicli are best. 
" The unsettled forms arising from crosses," Focke 
writes, "are the plastic material out of which 
gardeners form their varieties." 

But even in the fruits, and other bud-propa- 
gated plants, crossing may often be used to as 
good advantage for the purpose of originating 
variation as it can in peas or buckwheat. It only 
requires a longer time to fix and select variations 
because the plants mature so slowly. Ordinarily, 
if the operator does not find satisfactory plants 
amongst the seedlings of any cross of fruit trees, 
he roots up the whole batch as profitless. But if 
he were to allow the best plants to stand and 
were to sow seeds from them, the second gen- 
eration might produce something more to his 
liking. But it is generally quicker to make 
another cross and to try the experiment over 
again, than to wait for unpromising seedlings to 
bear. This repeated repetition of the experiment, 
however, — continual crossing and sowing and 
uprooting, — is gambling. Throwing dice to see 
what will turn up is a comparable proceeding. 
The sowing of uncrossed seed is little better. 
Peter M. Gideon sowed over a bushel of apple 
seed, and one seed produced the Wealthy aj^ple.^ 

1 The facts in the origination of the Wealthy apple, as re- 
lated to me by Mr, Gideon, are these : he first planted a bushel 
of apple seeds, and then eacli year, for nine years, he planted 



GUIDES TO CROSSING. 109 

D. B. Wier raised a million seedlings of soft 
maple, and one plant of tlie lot had finely divided 
leaves, and is now Wier's Cutleaved maple. Teas' 
Weeping mulberry, which is now so deservedly 
popular, was, as INIr. Teas tells me, "merely an 
accidental seedling." So this explains why the 
production of new varieties of fruits is always 
chance, whilst a skilled man can sit in his study 
in the winter time and picture to himself a new 
bean or muskmelon, and then go out in the next 
three or four summers and produce it. 

9. If it is desired to einploy crossing as a direct 
memis of producing neiv varieties^ each parent to the 
projjosed cross should be selected in agreement ivith 
the rules already specified^ and also because it pos- 
sesses in an emphatic degree one or more of the 
qualities tvhich it is desired to combine; and the 
more uniformly and persistently the p)arent pre- 
sents a given character^ the greater is the chance that 
it ivill transmit that character. It has already 
been said that crossing for the instant production 
of new varieties is most certain to give valuable 

enough seed to give a thousand trees. At the end of ten years, 
all the seedlings had perished (this was in Minnesota) except 
one hardy seedling crab. Then a small lot of seeds of apples 
and crab apples was obtained in Maine, and from these the 
Wealthy came. There were only about fifty seeds in the 
batch of crab seed which gave the Wealthy ; but before this 
variety was obtained, much over a bushel of seed had been 
sown. 



110 HOW DOMESTIC VARIETIES ORIGINATE. 

results in those species which are propagated by 
buds, because the initial individual differences 
are not dissipated by seed-reproduction. This 
is especially true of hybridization, or crossing 
between distinct species ; for in such violent cross- 
ing as this the offspring is particularly likely to 
be unstable when propagated by seeds. The re- 
sults of hybridization appear to be most certain 
in those plants which are grown under glass, and 
in whicli, therefore, the selection of the seed- 
parents is most carefully made, and where the 
conditions of existence are most uniform. The 
most remarkable results in hybridization which 
have yet been attained are with the choicer glass- 
house plants, such as orchids, begonias, anthu- 
riums, and the like. (Lecture II.) 

The more violent the cross, the less is the likeli- 
hood that desirable offspring will follow. Species 
which refuse to give satisfactory results when 
hybridized directly or between the pure stocks, 
may give good varieties when the " blood " has 
become somewhat attenuated through previous 
crossings. The best results in hybridizing our 
native grape with the European grape, for ex- 
ample, have come from the use of one parent 
which is already a hybrid. Two notable examples 
are the Brighton and Diamond grapes, raised by 
Jacob Moore. The Brighton is a cross of Con- 
cord (pure native) by Diana-Hamburg (hybrid of 



IMPORTANT HYBRIDS OF FRUITS. Ill 

impure native and European). Diamond is a 
cross of Concord by lona, the latter parent un- 
doubtedly of impure origin, containing a trace of 
the European vine. T. V. Munson's Brilliant is 
a secondary hybrid, its parents, Lindley and Dela- 
ware, both containing hybrid blood. Others of 
his varieties have similar histories. Even when 
the cross is much attenuated — or three or four 
or even more times removed from a pure hybrid 
origin by means of subsequent crossings — it may 
still produce marked effects in a cross without 
introducing such contradictory characters as to 
jeopardize the value of the offsj)ring. 

Amongst American fruit plants there are com- 
paratively few valuable hybrids. The most con- 
spicuous ones are in the grapes, particularly the 
various Rogers varieties, such as Agawam, Lind- 
ley, Wilder, Barry, and others, which are hybrids 
of the European grape and a native species. 
Other hybrids are the Kieffer and allied pears 
(between the common pear and the Oriental 
pear), the Transcendent and a few other crabs 
(between the common apple and the Siberian 
crab), the Soulard and kindred crabs (between 
the common apple and the native Western crab), 
a few blackberries of the Wilson Early type 
(between the blackberry and the dewberry), the 
purple-cane raspberries (between the native red 
and black raspberries, and possibly sometimes 



112 HOW DOMESTIC VARIETIES ORIGINATE. 

combined with the European raspberry), the 
Utah Hybrid cherry (between the Western sand 
cherry and the sand plum), and probably a few 
of the native plums. There is undoubtedly a 
fertile field for further work in hybridizing our 
fruits, particularly those of native origin, and 
also many of the ornamental plants ; the danger 
is that persons are apt to expect too much from 
hybridization, and too little from the betterment 
of all the other conditions Avhicli so profoundly 
modify plants. Violent hybridizations generally 
give unsatisfactory and unreliable results ; but 
subsequent crossings, when the "blood" of the 
original species to the contract is considerably 
attenuated, may be expected to correct or over- 
come the first incompatibility, as explained above. 
10. Edahlisli the ideal of the desired variety 
firmly in the mind before any attempt is made at 
pla7it-breeding. If one is to make any j^rogress 
in securing new varieties, he must first be an 
expert judge of the capabilities and merits of 
the plants with which he is dealing, otherwise 
he may attempt the impossible or he may obtain 
a variety which has no merit. It is important, 
too, that the person bear in mind the fact that 
a variety which is simply as good as any other 
in cultivation is not worth introducing. It 
should be better in some particular than any 
other in existence. The oj^erator must know the 



PRODUCE AN INITIAL VAKIATION. 118 

points of Lis plant, as an expert stock-breeder 
knows the points of an animal, and he must 
possess the rare judgment to determine which 
characters are most likely to reaj^pear in the 
offspring. Inasmuch as a person can be an ex- 
pert in only a few jDlants, it foUoAvs that he can- 
not expect satisfactory results in breeding any 
species which may chance to come before him. 
Persistent and uniform effort, continued over a 
series of years, is generally demanded for the 
production of really valuable varieties. Thus it 
often haj)pens that one man excels all competitors 
in breeding a particular class of plants. The hor- 
ticulturist will recall, for instance, Lemoine in 
the breeding of gladiolus, Eckford in peas, Crozy 
in cannas, Bruant in pelargoniums, and others. 
There are now and then varieties which arise 
from no effort, but because of that very fact they 
reflect no credit upon the so-called originator, 
who is really only the lucky finder. So far as 
the originator is concerned, such varieties are 
merely chance. If, however, the operator -— him- 
self an expert judge of the plant with which he 
deals — chooses his seeds with care and discrimi- 
nation, and then proposes, if need be, to follow up 
his work generation by generation by means of 
selection, the work becomes plant-breeding of the 
highest type. 

First of all, therefore, the operator must know 



114 HOW DOMESTIC VARIETIES ORIGINATE. 

what he can likely get, and Avliat will likely be 
worth getting. Most persons, hoAvever, begin at 
the other end of the problem, — they get what 
they can, and then let the public judge if the 
effort has been worth the while. 

11. Having obtained a specific arid correct ideal, 
the operator must next seek to make his plant vary 
in the desired direction. This may be done by 
crossing, or by modifying the conditions under 
which the plant grows, as indicated in Lectures 
I. and II. If there are any tAvo plants Avhich 
possess indications of the desired attributes, cross 
them: amongst the seedlings there may be some 
which may serve as starting-points for further 
effort. 

A change in the circumstances or environment 
of the plant may start the desired attribute. If 
the plant must be dAvarfer, plant it on poorer or 
drier soil, transfer it toAvards the poles, plant it 
late in the season, or transplant it repeatedly (see 
pages 25 and 143). DAvarf peas become climb- 
ing peas on rich, moist soils. If the plant must 
have large fruits, alloAV it more food and room, 
and give attention to pruning and thinning. Cer- 
tain geographical regions develop certain charac- 
ters in plants, as we have seen (page 24); if, 
therefore, the desired feature does not appear 
spontaneously or as a result of any other treat- 
ment, transfer the plant for a time to that region 



PRODUCE AN INITIAL VARIATION. 115 

which is characterized by such attributes, if there 
is any such. 

The importance of growing the plant under 
conditions or environments in which the desired 
type of characters is most frequently found, is 
admirably emphasized in the evolution of varieties 
which are adapted to forcing under glass. AVithin 
a century, — and in many instances within a 
decade or two, — sj^ecies which were practically 
unknown to glass-houses have produced varieties 
which are perfectly adapted to them. This has 
been accomplished by growing the most tractable 
existing varieties under glass, and then carefully 
and persistently selecting those which most com- 
pletely adapt themselves to their environment and 
to the ideals of the operator. One of the most 
remarkable examples of this kind is afforded by 
the carnation. In Europe it is chiefly a border 
or out-door plant, but wdthin a generation it has 
produced hosts of excellent forcing varieties in 
America, where it is grown almost exclusively as 
a glass-house flower. So the carnation types of 
Europe and America are widely unlike, and the 
unlikeness becomes more emphatic year by year 
because of the rapid aberrant evolution of the 
American forms. 

Sowing the seeds of hardy annual plants in the 
fall often generates a tendency to produce thick- 
ened roots. The plant, finding itself unable to 



116 HOW DOMESTIC VARIETIES ORIGINATE. 

perfect seeds, stores its reserve in the root, and 
it therefore tends to become Lienniah In this 
manner, with the aid of selection and the varia- 
tion of the soil, Carriere was able to produce good 
radishes from the wild slender-rooted charlock 
(Raphanus RaxDhanistrum) . 

Lessened vigor, so long as the plant continues 
to be healthy, nearly always results in a compara- 
tive increase of fruits or reproductive organs. 
It is an old horticultural maxim that checking 
growth induces fruitfulness. It is largely in con- 
sequence of this fact that plants bear heaviest 
when they attain approximate maturity. Trees 
are often thrown into bearing by girdling, heavy 
pruning, the attacks of borers, and various acci- 
dental injuries. The gardener knows that if he 
keeps his volants in vigorous growth by con- 
stantly potting them on into larger pots, he will 
get little, or at least very late, bloom. The 
plant-breeder, therefore, may be able to induce 
the desired initial variation by attention to this 
principle. (See discussion of variation in rela- 
tion to food supply, page 16.) Arthur has re- 
cently put the principle into this formula : " A 
decrease in nutrition during the period of growth 
of an organism, favors the development of the re- 
productive parts at the expense of the vegetative 
parts." 

A most important means of inducing variation 



SIMULTANEITY OF VARIATION. 117 

is the simple change of seed, the philosophical 
reasons for which are explained on pages 59 and 
28. A plant becomes closely fitted or accus- 
tomed to one set of conditions, and when it is 
placed in new conditions, it at once makes an 
effort to adapt itself to them. This adaptation 
is variation. No doubt the free interchange of 
seeds between seed-merchants and customers is 
one of the most fertile causes of the enormous 
increase in varieties in recent times. 

When once a novel variety appears, others of a 
similar kind are likely soon to follow in other 
places, and some persons have supposed that there 
is a synchronistic variation in plants, or a tendency 
for like variations to appear simultaneously in 
widely separated localities. There is perhaps 
some remote reason for this belief, because there 
is, as Darwin expresses it, an accumulative effect 
of domestication or cultivation, by virtue of which 
plants which long remain comparatively invariable 
may within a short time, when cultivation has 
been continued long enough, vary widely and in 
many directions; and it is to be expected that 
even when plants have long since responded to 
the wishes of the cultivator, an equal amount or 
accumulation of the force of domestication would 
tend to produce like effects in different places. 
But it is probable that by far the greater part of 
this synchronistic variation is simply an apparent 



118 HOW DOMESTIC VARIETIES ORIGINATE. 

one, for whenever any marked novelty appears the 
attention of all interested persons is directed to 
looking for similar variations amongst their own 
plants. 

12. The person who is wishing for neiv varieties 
should look critically to all perennial plants^ and 
particulay'ly to trees and shrubs^ for hud-varieties 
or sports. It has already been said (pages 28, 6) 
that the branches of a tree may vary amongst 
themselves in the same Avay in which seedlings 
vary, and for the same reasons. As a rule, any 
marked sport is capable of being perpetuated by 
bud-propagation. The number of bud- varieties 
noAv in cultivation is really very large. Many of 
the cut-leaved and colored or variegated varieties 
of ornamental plants were originally found upon 
other trees as sports. The " mixing in the hill " 
of potatoes is bud-variation. Nectarines are 
derived from the peach, some of them as sports 
and some as seedlings. The moss-rose was prob- 
ably originally a sport from the Provence rose. 
Greening apple trees often bear russet apples, and 
russet trees sometimes bear greenings. So far as 
I know, there are no varieties of annual plants 
which have originated as sports. The probable 
reason for this is the fact that the duration of the 
plant is short and that its constitution is not pro- 
foundly modified in a single generation by the 
new circumstances in which it is placed every 



BUD- VARIETIES. 119 

year. The effects of the conditions in which it 
lives are recorded in the seeds, and the plant dies 
without allowing a second season of growth to 
express the impressions which were received in 
a former generation. The fact that every branch 
of an annual plant — as of perennials — is unlike 
every other branch, is evidence enough that the 
annual is not unlike the perennial in fundamental 
constitution ; and there is every reason to believe 
that if any given annual were to become a peren- 
nial, it would now and then develop differences 
sufficiently pronounced to make them worthy the 
name of sports, the same as hyacinths, bouvardias, 
trees, and all other perennial plants are apt to do. 
Bud-varieties may not only come true from buds 
— as grafts, cuttings and layers, — but they occa- 
sionally perpetuate themselves by seeds. Now, 
these seedlings are amenable to selection, just the 
same as any other seedlings are ; the bud-variety, 
therefore, may give the initial starting-point for 
plant-breeding. But, more than this, it is some- 
times possible to improve and fix the type by 
bud-selection as well as by seed-selection. Dar- 
win cites this interesting testimony : " Mr. Salter 
brings the principle of selection to bear on varie- 
gated plants propagated by buds, and has thus 
greatly improved and fixed several varieties. He 
informs me that at first a branch often produces 
variegated leaA^es on one side alone, and that the 



120 HOW DOMESTIC VARIETIES ORIGINATE. 

leaves are marked only with an irregular edging, 
or with a few lines of white and yellow. To im- 
prove and fix such varieties, he finds it necessary 
to encourage the buds at the bases of the most 
distinctly marked leaves and to propagate from 
them alone. By following, with perseverance, this 
plan during three or four successive seasons a dis- 
tinct and fixed variety can generally be secured." 
Ernest Walker, a careful gardener at New Albany, 
Indiana, is of the opinion that the abnormal char- 
acter of sports often intensifies itself if the sport 
is allowed to remain upon the parent plant for a 
considerable time. He has observed this particu- 
larly in coleus, where color sports are frequent. 
"In these," he says, "the sport begins with a 
branch, Avhich may be taken off and propagated as 
a new variety. If left on the parent, other parts 
of the plant are apt to sliow similar variations. 
Indeed, I think it is not best to be in too great a 
hurry to remove a sporting branch, for its char- 
acter seems to tend to become more fixed if it 
remains on the plant." 

13. The starting -point once given^ all permanent 
progress lies in continued selection. This, as I have 
already pointed out, is really the key to the whole 
matter. In the greater number of cases, the oper- 
ator cannot produce the initial variation which he 
desires, but, by looking carefully amongst many 
plants, lie may find one which shows an indication 



SELECTION THE KEY-NOTE. 121 

of his ideal. This plant must he carefully saved, 
and all the seeds sown in a place where crossing 
with other types cannot take place. Of a hun- 
dred seedlings from this plant, mayhap one or 
two will still further emphasize the character 
Avhich is sought. These, again, are saved and all 
the seeds are sown. So the operation goes on, 
patiently and persistently, and there is reward 
at the end. This is the one eternal and funda- 
mental principle which underlies the amelioration 
of j)lants under the touch of man ; and because 
we know, from experience, that it is so important, 
we are sure, as Darwin was, that selection in 
nature must be the most potent factor in the 
progress of the vegetable world. 

But suppose this suggestion of the new variety 
does not appear amongst the batch of plants 
which we raise ? Then sow again ; vary the con- 
ditions ; select the most widely variable ty]Des ; 
cross ; at length — if the ideal is true — the sug- 
gestion will come. " Cultivation, diversification 
of the conditions of existence, and repeated sow- 
ings " are the means which Yerlot would employ 
to induce variations. But the skill and the char- 
acter of the final result lie not so much in the 
securing of the initial start, as in the subsequent 
selection. Nature affords starting-points in end- 
less number, but there are few men alert and skil- 
ful enough to take the hint and improve it. If I 



122 HOW DOMESTIC VAIUETIES ORIGINATE. 

want a new tomato, I first endeavor to discover 
what I want. I decide that I mnst have one like 
the Acme in color, bnt more spherical, with a 
firmer flesh, and a little earlier. Then I shall 
raise an acre of Acme tomatoes, and closely allied 
varieties ; or if I cannot do that, I make arrange- 
ments to inspect my neighbor's fields. I scruti- 
nize every plant as the first fruits are ripening. 
Finally, I find one plant — not one fruit — which 
is something like the variety Avhich I desire. 
Very well ! Wait two to five years, and you shall 
see my new A^ariety ! 

Some of these initial variations possess no ten- 
dency to reproduce themselves. The seedlings of 
them may break up into a great diversity of 
forms, no form representing the parent closely. 
In such cases, it is generally useless to proceed 
further with this brood. Another start should be 
made with another plant. So it is always impor- 
tant, as we have already seen (Rule 6), to have as 
many starting-points as possible, to lessen the risk 
of failure. Whilst it requires nice judgment to se- 
lect those plants which possess the most important 
and the most transmissible combination of charac- 
ters, the greatest skill is nevertheless required to 
carry forward a correct system of selection. 

14. Even ivlien the desired variety is obtained, it 
must he hept up to the standard by constant attention 
to selection. That is, there is no real stability in 



SELECTION TO MAINTAIN PUKITV. 12B 

the forms of plant life. So long as the conditions 
of existence vary, so long will plants make the 
effort to adapt themselves to the changes. No 
two seasons are alike, and no two fields, or even 
parts of fields, are alike ; and there are no two 
cultivators who give exactly the same and equal 
attention to tillage, fertilizing, and the other 
treatments of plants. All forms or varieties, 
therefore, tend to "run out" by variation or 
gradual evolution into other forms ; but because 
we keep the same name for all the succeeding 
generations, we fancy that we still have the same 
variety. In 1887 I found a single tomato plant 
in my garden in Michigan, which had several 
points of superiority over any other of the one 
hundred and seventy varieties which I was then 
growing. It came from a packet of German seed 
of an inferior variety. The tomato was very 
solid, an unusually long keeper, productive, and 
attractive in sii^e and appearance. The variation 
was so promising that I named it in a sketch of 
tomatoes which I published that year, calling it 
the Ignotum (that is, unknown), to indicate that 
the origin of it was no merit of my own. I sent 
seeds to a few friends for testing. I sowed the 
seeds for about five hundred plants m 1888 m 
an isolated patch upon uniform soil. The larger 
part of the plants were more or less like the 
parent. A few reverted. A few of the best 



124 HOW DOMESTIC VARIETIES ORIGINATE. 

plants were selected, and the seed saved. I 
then moved to New York and took the seed with 
me. This was sown in uniform soil in an iso- 
lated position in 1889. This ci'op, probably as 
a result of the careful selection of the year before 
and of the change of locality, was remarkably 
uniform and handsome. Of the 442 plants which 
I grew that year, none reverted to the little 
Eiformige Dauer, the German variety from which 
it had come, but there was some variation in them 
due to different methods of treatment. I again 
saved the seeds, and I was now ready to intro- 
duce the variety. I therefore sold my seed, six 
pounds, to y. H. Hallock & Son, Queens, New 
York, who introduced it in 1890. The very next 
year, 1891, I obtained the Ignotum from fifteen 
dealers and grew the plants side by side. Of the 
fifteen lots, eight bore small and poor fruits which 
were not worth growing and which could not be rec- 
ognized as Ignotum ! Grown from our own seed, 
it still held its characters well. Here, then, only 
a year after its introduction, half the seedsmen 
were selling a spurious stock. It is possible that 
some of this variation arose from substitution of 
other varieties by seedsmen, although I have yet 
secured no evidence of any unfair dealing. It is 
possible, also, that the product of some of the 
samples which I early sent out for testing had 
found their way into seedsmen's hands. But I am 



DURATION OF VARIETIES. 125 

convinced that very much of this variation was 
a legitimate result of the various conditions in 
which the crops of 1890 had been grown, and the 
varying ideals of those who saved the seeds. I 
am the more positive of this from the fact that 
the Ignotum tomato, as I first knew it and bred 
it, appears to be lost to cultivation, althoug^h the 
name is still used for the legitimate family of 
descendants from my original stock. All this 
experience illustrates how quickly varieties pass 
out by variation and by the unconscious and 
unlike selection practised by different persons. 

The duration of any variety is inversely propor- 
tional to the frequency of its generations. Annual 
plants, other conditions being the same, run out 
sooner than perennials, because seed-reproduc- 
tion — or the generations — intervenes more fre- 
quently. Trees, on the other hand, carry their 
variations longer, because the seed-generations — 
in which departures chiefly take place — are far- 
ther apart. Of all the so-called fruit plants, the 
strawberry runs out soonest and the varieties 
change the oftenest, because a new generation can 
be brought into fruit-bearing in two years, whilst 
it may require a decade or more to bring a new 
generation of apples or chestnuts into bearing. 
Yet, my reader will remind me that the Wilson 
strawberry has been and is the leading variety in 
many places for nearly forty years, to which I 



126 HOW DOMESTIC VAIMETIES ORIGINATE. 

reply tliat the Wilson of to-day is not necessarily 
the same as that introdnced by James Wilson, 
simply because the name is the same. Every dif- 
ferent soil or treatment tends to produce a different 
strain or variation in the Wilson straAvberry, as it 
does in any other plant ; and every grower, when 
settiAg a new plantation, selects his plants from 
that part of his field which pleases him best, 
rather than from those plants which most nearly 
correspond to the original type of the Wilson. 
That is, this unconscious selection on the part of 
the grower takes no account of what the variety 
was, but only of what it ought to be, and this 
ideal differs with every person. It is not surpris- 
ing, therefore, to find strains of Wilson strawberry 
which are as unlike as many named varieties are ; 
and it is to be expected that all of the strains now 
in existence have departed considerably from the 
original type. 

This example borrowed from the strawberry is 
a most important one, because it illustrates how a 
variety may vary and pass out of existence even 
though it is propagated wholly asexually, or by 
buds. There are to-day several different types of 
Rhode Island Greening apple in cultivation, which 
have originated from variations produced by envi- 
ronment and by the different models which propa- 
gators have had in mind ; and the same is true of 
many other fruits. 



AMELIORATION DUE TO SELECTION. 127 

All the foregoing remarks demonstrate the 
hnportance of constant attention to selection if 
one desires to maintain the exact type of any 
variety which he has prodnced. They explain 
the value of the '' roguing " — or systematic de- 
struction of all " rogues " or non-typical plants — 
which is invariably practised by all good seed- 
growers. But they still more emphatically show 
that every variety is essentially unstable, and that 
the only abiding result is constant evolution, the 
old forms being left behind as the type expands 
into new and better strains. Varieties to be valu- 
able, therefore, ought not to be rigidly fixed, and, 
fortunately, nature has prescribed that they can- 
not be. Probably every decade sees a complete 
change in every variety of any annual species 
Avhicli is propagated exclusively from seeds, and 
every century must see a like change in the tree 
fruits. These changes are so gradual, and the 
original basis of comparison fades away so com- 
pletely, that we generally fail to recognize the 
evolution. 

15. It is evident^ therefore^ that the 7nost abiding 
progress in the aynelioration of plants must come as a 
residt of the very best cidtivation and the 7nost intel- 
ligent selection and change of seed. Every reflec- 
tive person must admit that the cultivation of 
plants — which is the fundamental conception of 
agriculture — has been and is crude and imperfect, 



128 HOW DOMESTIC VAlilETIES ORIGINATE. 

and that there has been no conscious effort on the 
part of the human race to produce any given final re- 
sult upon the cultivated flora. Yet, this imperfect 
cultivation has already modified plants so pro- 
foundly that we cannot determine the originals of 
many of them, and we can trace the evolution of 
but few. The science of rural industry is now 
fairly Avell understood in its essential fundamental 
principles, and the intelligence of those classes of 
persons who deal with plants is rapidly enlarging. 
The opening of the twentieth century will virtu- 
ally mark a new era for agriculture, and from 
that time on the onward evolution of plants should 
proceed confidently and unchecked. Our eyes are 
too often dazzled by the novelties which suddenly 
thrust themselves upon us, and Ave look for some 
mystic power which shall enable us to produce 
varieties forthwith at our will. We need not so 
much varieties with new names as we do a general 
increase in productiveness and efficiency of the 
types which we already possess ; and this augmen- 
tation must come chiefly in the form of a gradual 
evolution under the stimulus of good care. The 
man who will accomplish most for the amelioration 
and unfolding of the forms of plants, is he Avho 
fixes his eyes steadily upon the future, and with 
the inspiration of a long forecast, urges the better- 
ment of all conditions in which plants grow. 



DEWBERRY AND BLACKBERRY. 129 

III. Specific Examples. 

The foregoing principles and discussions will 
become more concrete if a few actual examples of 
the origination of varieties are given. In order 
to begin with a very simple case, I will relate the 
introduction of the varieties of dewberries, for 
this fruit is yet little cultivated, the varieties are 
few, and the domestication of it is not yet thirty 
years old. 

The Dewberry and Blackberry. 

The dewberries are native fruits, and it is only 
within the last ten years that they liave become 
prominent among fruit-growers. The most impor- 
tant one is the Lucretia. This was found grow- 
ing wild upon a plantation in West Virginia in 
war time. In 1876, a few of the plants were sent 
to Ohio, and from this start the present stock has 
come. It is probable that similar wild varieties are 
growing to-day in many parts of the country, but 
they have not chanced to have been seen by per- 
sons who are interested in cultivating them. It is 
a form of the common wild dewberry, which grows 
all over the northeastern states. Just why this 
particular patch in West Virginia should have been 
so much better than the general run of the species, 
nobody knows, but it was undoubtedly the prod- 
uct of some local environment of soil or position. 

K 



130 HOW DOMESTIC VAIIIETIES ORIGINATE. 

Early in the seventies, T. C. Bartel, of Huey, 
Clinton Co., Illinois, observed very excellent dew- 
berries growing in rows between the lines of 
stubble in an old cornfield, where the plant had 
evidently been quick to avail itself of unoccupied 
land. This was introduced as the Bartel dew- 
berry, and is now the second in point of promi- 
nence amongst the cultivated varieties. Other 
varieties have appeared in much the same way. 
A fruit-grower in Michigan found an extra good 
dewberry in a neighboring wood-lot, and intro- 
duced it under the name of Geer, in compliment 
to the owner of the place. In Florida, an un- 
usually good plant of the common wild dewberry 
of that region was discovered, and introduced by 
Reasoner Brothers, under the name of Manatee. 
There are now about twenty named varieties of 
dewberries in cultivation, as described in our 
horticultural writings, all of which, so far as I 
know, are chance plants from the wild. 

As the dewberries become more widely grown, 
good seedlings will now and then appear in cul- 
tivated ground, and these will be named and 
sold. After a time persons will begin to sow 
seeds for the purpose of producing new varieties ; 
and those seedlings which chance to possess un- 
usual merit will be propagated, and in due time 
introduced. This is the history of the cultivated 
blackberries and raspberries which have come 



EVOLUTION OF THE APPLE 131 

from the wild plants in less than half a century. 
These fruits are now so far developed that we no 
longer think of looking to the woods and copses 
for new varieties of promise, but the novelties are 
mostly chance seedlings from cultivated varieties. 
A few years ago a friend purchased plants of the 
Snyder blackberry. When they came into bear- 
ing he noticed that one plant was better than the 
rest. It bore larger fruits, and the bearing season 
was longer. He took suckers from this plant, 
and from these others Avere taken, until he now has 
a large plantation of the novelty, mostly selected 
from plants which pleased him best. The variety 
has such distinct merit that I have named it the 
Mersereau, in honor of the man wdio recognized 
and propagated it. He will continue selecting 
from the best plants, as he propagates year by 
year, and it may be that in a few years he will 
have so much improved it that it will no longer 
be the variety with which he started. 

The Apple. 

The original apple is not definitely known, but 
it was certainly a very small and inferior, crabbed 
fruit, borne mostly in clusters. When we first 
find it described by historians, it was still of small 
value. Pliny said that some kinds were so sour 
as to take the edge off a knife. But better and 



132 HOW DOMESTIC VAKIETIES ORIGINATE. 

better seedlings continued to come np about habi- 
tations, until, when printed descrij^tions of fruits 
began to be made, three or four hundred years 
ago, there Avere many named kinds in existence. 
The size had vastly improved, and with this in- 
crease came the reduction of the number of fruits 
in the cluster; so that, at the present time, whilst 
apple flowers are borne in clusters, the fruits are 
generally borne singly. That is, most of the 
flowers fail to set fruit, and they complete their 
mission when they have shed their pollen for the 
benefit of the one which persists. 

The American colonists brought with them the 
staple varieties of the mother countries. But 
the needs of the new country were unlike those 
of the old, and the tastes and fashions of the 
people were changing. So, as seedlings came up 
about the buildings and along the fences, where 
the seeds had been scattered, the ones which prom- 
ised to satisfy the new needs best were saved, and 
many of the old varieties were allowed to pass 
away. In 1817, the date of the first American 
fruit-book, over sixty per cent of the varieties 
particularly recommended for cultivation in this 
country were of American origin. In 1845, 
nearly two hundred varieties of apples Avere de- 
scribed as having been fruited in this country, 
of which over half were of American origin. Be- 
tween these two dates, introductions of foreign 



EVOLUTION OF THE APPLE. 133 

varieties liad been freely made, so that the per- 
centage of domestic varieties had fallen. But 
the next thirty years saw a great change. Of 
1823 varieties described in 1872, nearly or quite 
seventy per cent were American, and a still greater 
proportion of the most prized kinds were of 
domestic origin. In the older states, the apple 
had now become so thoroughly accustomed to its 
environment, and the tastes of the people were 
so Avell supplied, that there was no longer much 
need for the introduction of foreign kinds. It 
was not so in the Northwest. There the apples 
of the eastern states did not thrive. The climate 
was too cold and too dry. Attention was turned 
to other countries with similar or rigorous cli- 
mate. In 1870, the Department of Agriculture 
at Washington imported cions of many varieties 
of apples from Russia; but these did not satisfy 
many fruit-growers of the northern states. It 
was then conceived that the great interior plain 
of Russia should yield apples adapted to the upper 
Mississippi valley, whilst those already imported 
had come from the seaboard territory. Accord- 
ingly, early in the eighties, Charles Gibb, of the 
province of Quebec, and Professor Budd, of Iowa, 
went to Russia to introduce the promising fruits 
of the central plain. The result has been a most 
interesting one to the pacific looker-on. There 
are ardent advocates of the Russian varieties, and 



134 HOW DOMESTIC VARIETIES ORIGINATE. 

there are others who see nothing good in them. 
There are those who believe that all progress 
must come by securing seedlings from the hardi- 
est varieties of the eastern states; there are others 
who would derive everything from the Siberian 
crabs, and still others who believe that the final 
result lies in improving the native crabs. There 
is no end of discussion and cross-purposes. In 
the meantime, nature is quietly doing the work. 
Here is a good seedling of some old variety, there 
a good one from some Russian, and now and then 
one from the crab stocks. The new varieties are 
gradually supplanting the old, so quietly that few 
people are aware of it; and by the time the con- 
testants are done disputing, it will be found that 
there are no Russians and no eastern apples, but 
a brood of northwestern apples which have grown 
out of the old confusion. 

All these new apples are simply seedlings, 
almost all of them chance trees which come up 
here and there wherever man has allowed nature 
a bit of ground upon which to make garden as 
she likes. In 1892, there were 878 varieties of 
apples offered for sale by American nurserymen, 
and it is doubtful if one in the whole lot was the 
result of any attempt on the part of the originator 
to produce a variety with definite qualities. And 
what is true of the apple, is about equally true 
of the other tree fruits. In the small fruits and 



BEANS. 135 

the grapes, where the generations are shorter and 
the results quicker, more has been done in the 
way of direct selection of seeds and the crossing 
of chosen parents; but even here, the methods 
are mostly haphazard. 

Beans. 

Perhaps there are no plants more tractable in 
the hands of the plant-breeder than the garden 
beans. Some two or three years ago, a leading 
eastern seedsman conceived of a new form of bean 
pod which would at once commend itself to his 
customers. He was so Avell convinced of the 
merits of this prospective variety, that he made 
a descriptive and " taking " name for it. He then 
wrote to a noted bean-raiser, describing the ^yo- 
posed variety and giving the name. *' Can you 
make it for me ? " he asked. '' Yes, I will make 
you the bean," replied the grower. The seeds- 
man then announced in his catalogue that he 
would soon introduce a new bean, and, in order 
to hold the name, he published it, along with the 
announcement. Two years later, I visited the 
bean-grower. '' Did you get the bean ? " I asked. 
"Yes, here it is." Sure enough, he had it, and it 
answered the requirements very well. Another 
seedsman would like a round-podded, stringless, 
green-podded bean. This same man ]3roduced 



136 HOW DOMESTIC VARIETIES ORIGINATE. 

it, and I went into a field of fifteen acres of it, 
where it was growing for seed, and the most fas- 
tidious person coukl not have asked for a closer 
approach to the ideal which the breeder had set 
before him some four or five years before. 

How is all this done ? It looks simple enough. 
The ideal is established first of all. The breeder 
revolves it in his mind, and eliminates all the 
impracticable and contradictory elements of it. 
Then he goes carefully and critically through his 
bean fields, particularly those varieties which are 
most like the desired kind, and marks those plants 
which most nearly approach his ideal The seeds 
of these are carefully saved, and they are planted 
in isolated positions. If he finds no promising 
variations amongst his plantations, then he must 
start off the variation in some other way. This 
is usually done by crossing those varieties which 
are most like the proposed kind. He has got a 
start ; but noAv the science and skill begin. Year 
by year he selects just those plants Avhich please 
him best and which he judges, from experience, 
will most surely carry their features over to the 
offspring. He starts with one plant ; the next 
year he may have only two. If he has ten or 
twenty good ones, then the task is an easy one, 
for the variety has elements of permanence — that 
is, of hereditability — in it. But he may have no 
plants the second year. In that case, he begins 



BEANS. 13T 

again : for if the ideal is true, it can be attained. 
This bean-breeder to whom I have referred, and 
upon whom many of our best seedsmen rely for 
new varieties, tells me that he has discarded fully 
three thousand varieties and forms as jjrolitless. 
This only means that he is a most astute judge 
of beans, and that he knows when any type is 
likely to x^rove to be a poor breeder. 

The bean also affords an excellent example of 
the care which it is generally necessary to exercise 
to keep any variety true to the type. The person 
of whom I have spoken, in common with all care- 
ful seed-growers, searches his field with great 
pains to discover the ''rogues," or those plants 
which vary perceptibly from the type of the given 
variety. The rogue may be a variation in size or 
habit of plant, season of maturity, color or form 
of pods, productiveness, susceptibility to rust, or 
other aberrance. In the dwarf or bush beans, 
which are now most exclusively grown, the most 
frequent rogue is a climbing or half-climbing 
plant. This is a reversion to the ancestral type 
of the bean, which was no doubt a twining plant. 
This rogue is always destroyed, even though it 
may be, itself, a good bean. In some cases, the 
men who perform the roguing are sent along 
every row of a whole field on their hands and 
knees, critically examining every plant. The ef- 
fect of this continual selection is always to push 



138 HOW DOMESTIC VARIETIES ORIGINATE. 

on the variety to greater excellence. The vari- 
ous " improved " strains of plants are obtained in 
essentially this fashion. If the grower has been 
painstaking with his roguing, he soon finds that 
his seed gives better and more uniform crops than 
the common stock of the variety. If the improve- 
ment is marked, he may dignify his strain with 
a distinct name, and it thereby becomes a new 
variety. The improvement may be a very im- 
portant one to a careful bean-grower, and at the 
same time be so slight as to escape the attention 
of the general farmer, or even of experimenters 
who are not particularly skilled in judging the 
merits of beans. 

All these examples draAvn from the bean are 
excellent illustrations of the best and most scien- 
tific plant- breeding, and the same methods — varied 
to suit the different needs — apply to the ameliora- 
tion of all other plants. The recent dwarf Lima 
beans may be cited as examples of accidental or 
fortuitous varieties, in which the preconstructed 
ideal of the plant-breeder, had no place. Four or 
five of these beans have attained some prominence. 
Henderson and Kumerle dwarf Limas were intro- 
duced in 1889, Burpee in 1890, and Barteldes in 
1892 or 1893. The variety which is now called 
the Henderson was picked up twenty or more 
years ago by a negro, who found it growing along 
a roadside in Virginia. It was afterwards grown 



BEANS. 139 

ill various gardens, and about 1885 it fell into the 
hands of a seedsman in Richmond. Henderson 
purchased the stock of it in 1887, grew it in 
1888, and offered it to the general public in 1889. 
The introduction of Henderson's bean attracted 
the attention of Asa Palmer, of Kennett Square, 
Pennsylvania, who had also been growing a dwarf 
Lima. He called upon Burpee, the well-known 
seedsman of Philadelphia, described his variety, 
and left four beans for trial. These were planted 
in the test grounds and were found to be valuable. 
Mr. Palmer's entire stock was then purchased, — 
comprising over an acre, which had been carefully 
inspected during the season — and Burpee Bush 
Lima was presented to the public in the spring of 
1890. Mr. Palmer's dwarf Lima originated in 
1883, when his entire crop of Large White (Pole) 
Limas Avas destroyed by cut-worms. He went 
over his field to remove the poles before fitting 
the land for other uses, but he found one little 
plant, about ten inches high, which had been cut 
off about an inch above the ground but which had 
re-rooted. It bore three pods, each containing one 
seed. These three seeds were planted in 1884, 
and two of the plants were dwarf, like the parent. 
By discarding all plants which had a tendency to 
climb, in succeeding crops, the Burpee Bush Lima, 
as we now have it, was developed. The Kumerle, 
Thorburn, or Dreer, Dwarf Lima originated from 



140 HOW DOMESTIC VAKIETIES ORIGINATE. 

occasional dwarf forms of the Challenger Pole 
Lima, which J. W. Kumerle, of Newark, New 
Jersey, found growing in his field. The stock 
which came from these selected dwarf plants was 
introduced by Thorburn and Dreer, under their 
respective names. The singular Barteldes Bush 
Lima came from Colorado, aud is a similar dwarf 
sport of the old White Spanish or Dutch Runner 
bean. Barteldes received about a peck of the 
seed and introduced it sparingly. It attracted 
very little attention, and as the following season 
was dry, Barteldes himself failed to get a crop, 
and the variety was lost to the trade. 

C annas. 

Few plants have shown more remarkable evolu- 
tions in very recent years than the cannas. At 
the present time, the Crozy cannas — so named 
from Crozy, of Lyons, France, who has introduced 
the greater number of them — are most popular. 
This type is often called the French Dwarf, or 
the Flowering Canna, and it is marked by a com- 
paratively low stature, and very large and showy 
spreading flowers in many colors, whereas the can- 
nas of a few years ago Avere very tall plants, Avith 
small and late dull red, narrow flowers, and they 
were groAvn exclusively for their foliage effects » 
How has this transformation come about? 



C ANN AS. 141 

In the first place, it should be said that there 
are many species of canna, and about a half dozen 
of these were well known to gardeners at the 
opening of the century. About 1830, the cannas 
began to attract much attention from cultivators, 
and the original species were soon variously hybrid- 
ized. Crossed seeds, and seeds from the succes- 
sive generations of hybrids, introduced a host of 
new and variable forms. The first distinct fash- 
ion in cannas seems to have been for tall, late- 
flowerino- forms. In 1848, Annee, a cultivator in 
France, sowed seeds of Canna Nepalensis, a tall 
oriental species, and there sprung up a race of 
plants which has since been known as Canna 
Annasi. It is probable that this Canna Nepalensis 
had become fertilized with other species growing 
in Annee's collection, very likely with Canna 
glauca. At any rate, this race of cannas became 
popular, and was to its time what the French 
dwarfs are to the present day. The plants were 
freely introduced into parks, beginning about 
1856, but their use began to wane by 1870 
or before. Descendants of this type, variously 
crossed and modified, are now frequently seen 
in parks and gardens. 

The beginning of the modern race of dwarf, 
large-flowered cannas was in 1863, when one of 
the smaller-flowered Costa Rican species (Canna 
Warscewiczii) was crossed upon a large-flowered 



142 HOW DOMESTIC VARIETIES ORIGINATE. 

Peruvian species (Canna iriclifiora). The off- 
spring of this union came to be called Canna 
Ehemanni. This hybrid has been again variously 
crossed with other species, and modified by culti- 
vation and selection, until the present composite 
type is the result. Seeds give new varieties; and 
any seedling which is worth saving is thereafter 
multiplied by divisions of the root, and the result- 
ing plants are introduced to commerce. 

These various examples are but types of what 
has been and can be accomplished in a given group 
of plants. There is nothing mysterious about the 
subject, so far as the cultivator is concerned. He 
simply sets his ideal, makes sure that it does not 
contradict any of the fundamental laws of devel- 
opment of the plant with which he is to work, 
then patiently and persistently keeps at his task. 
He must have good judgment, skill, and inspira- 
tion, but he does not need genius. 

"In the improvement of plants," writes Henri 
L. de Vilmorin, "the action of man, much like 
influences which act on plants in the wild state, 
only brings about slow and gradual changes, often 
scarcely noticeable at first. But if the efforts 
toward the desired end be kept on steadily, the 
changes will soon become greater and greater, and 
the last stages of the improvement will become 
much more rapid than the first ones." 



LECTURE IV. 

BORROWED OPINIONS; BEING EXTRACTS PROM 
THE WRITINGS OF B. VERLOT, E. A. CARRIERE, 
AND W. O. FOCKE. 

I. Verlot's Classification of Varieties of 
Ornamental Plants. 

Verlot (/SVr la Production et la Fixation des 
Varietes dans les Plantes d^ Ornement~) distributes 
the varieties of ornamental plants into sixteen 
groups. I shall now transcribe these groups, and 
under each shall give a very brief quotation or 
abstract of some of his remarks concerning them. 

1. Varieties distinguished hy diminution of stat- 
ure, or divarjing." — Dwarfing is one of the most 
frequent variations in the vegetable kingdom, but, 
unlike many similar phenomena in the animal 
kingdom, these dwarfs are nearly always very 
fertile. If we question the cultivators upon the 
subject, they respond that these variations are 
purely accidental, and that whenever the varia- 
tions offer any reward they are propagated and 
distributed. 

Dwarfing may be brought about by sowing the 
seeds in the autumn (page 115), and at the same 

143 



144 BORROWED OPINIONS. 

time successively transplanting the plants, as they 
need. Suppose, for example, we sow seeds of Co- 
reopsis tinctoria in August or September. When 
the plants have developed leaves, they are trans- 
planted, leaving sufficient space between them 
to allow of liberal growth. When the plants 
begin to touch each other, transplant again, per- 
haps three or even four times. The plants 
become strong, vigorous, and stocky ; we encour- 
age the development of the loAvest branches and 
thereby tend to shorten the leading stem, thus 
making the individual comparatively dwarf. The 
seeds saved from plants thus treated during several 
generations will be more apt to produce dwarf 
varieties than seeds taken from other plants. 
The greater part of dwarf varieties appear in 
those plants which are sown in autumn, and in 
those, if sown in spring, which are submitted to 
successive transplantings. Thus, amongst the 
annual species which we habitually sow in July 
and September, the following have produced dwarf 
varieties : — 

Calceolaria plantaginea. 

Senecio cruentus. 

Lychnis (or Agrostemma) Coeli-rosa. 

Coreopsis (or Calliopsis) tinctoria. 

Oenothera Drummondii. 

Helichrysum bracteatum. 

Leptosiphon densiflorus. 



verlot's classification. 145 

Diaiithus Chinensis. 
Scabiosa atropurpurea. 
Schizaiithus retusus. 
Iberis uiiibellata. 

Amongst those species which we sow in spring, 
but frequently transplant, the following have 
dwarf forms : — 

Impatiens Balsamina. 
Callistephus hortensis. 
Tagetes patula. 
Tagetes erecta. 
Tagetes signata. 

2. Varieties distinguished hy augmentation of 
stature^ or giayit forms. — These varieties result 
from various causes, amongst which are amount 
and fertility of soil, the employment of newly 
harvested seeds, and crossing. 

3. Hardy varieties. — These are produced by 
successive selections from the most hardy indi- 
viduals. Hardy races are also obtained by cross- 
ing with hardy species or types. Thus, the forms 
of Rhododendron arboreum are rendered hardier 
when crossed with R. Catawbiense. 

4. Large-floivered varieties. — These variations 
are ahvays due to a good soil which is rich in humus, 
and above all by thorough and intelligent cultiva- 
tion. These are easily fixed, but they pass away 



146 BORROWED OPINIONS. 

insensibly Avhen the conditions nnder wliich they 
were produced are neglected. This return to 
small flowers is well illustrated in the pansy. [All 
plants which are grown for the beauty of their 
flowers tend to increase the size of those organs, 
because of the vigor wliich comes of good care, 
and the selection which necessarily follows. The 
frequency of the varietal name ''grandiflora" is 
proof of this. As soon as the plant has made any 
perceptible gain in the size of its flowers, some 
nurseryman adds this adjective to its name, as in 
Hydrangea paniculata grandiflora. No doubt the 
name is sometimes bestowed without warrant, for 
the purpose of selling the plant. Frequently the 
catalogue-maker drops the proper specific name 
and uses the varietal adjective as if it were the 
legitimate name of the plant, as in Gazania grandi- 
flora, which is properly Gazania rigens, variety 
grandiflora.] 

5, 6. Earl II and late varieties. — The chief 
agency affecting the duration of plants is climate, 
and desired variations in earliness or Ipiteness are 
obtained by transporting the plants to those cli- 
mates which produce such effects as we seek, and 
growing them there for a time ; or we can procure 
seeds from such climates, if the given plants are 
already grown there. 

The age of the seed also has an influence upon 
the resultino^ individual : the fresher the seed, the 



yerlot's classification. 147 

more rapid its germination, and consequently the 
more prom]3t the development of the plant. We 
have reason to expect that fresh seeds will have a 
tendency to produce early varieties, and that, on 
the contrary, old seeds, by germinating more 
slowly, will produce variations more or less late. 
[Not only does the age of the seed seem to be 
important in this connection, but recent experi- 
ments seem to show that the degree of maturity 
also modifies the offspring. Seeds which are 
barely ripe enough to germinate have a tendency 
to give earlier progeny than those which are fully 
matured and ripened. See page 103.] 

The first seeds to mature on any plant may be 
expected to give early plants, and the subsequent 
seeds give later plants. [Verlot states that a cold 
region tends to make the plants later when trans- 
ferred to it, but this seems to be an error. The 
fact is generally just the reverse. Plants taken 
towards the poles or to higher altitudes, become 
earlier in two wa3^s, by shortening their period 
of growth, and by vegetating at a less sum- 
temperature in spring. See page 26.] 

7. Odoriferous varieties. — Odor varies greatly, 
even amongst varieties of one species. The causes 
of the differences in fragrance are not numerous 
and they are little understood. Climate, exposure, 
and the nature of the soil are leading factors. 
The odor of plants which grow on dry and arid 



148 BORRO^YED OPINIONS. 

hills is much more penetrating than that of the 
same species cultivated in humid and shady places. 
It is possible, even, to entirely change the odor by 
transporting the plant from one place to another. 
For example, Satyrium hircinum exhales a most 
pronounced goat -like odor in the vicinity of Paris 
and northward, whilst in the east, and particularly 
in the southern regions, its flowers have an odor 
which is somewhat like that of vanilla. 

8. Varieties tvith colored paints. — Coloration may 
be either complete or partial, and it may reside 
in any or all parts of the plant, as follows : — 

The stems. 
The leaves. 

The flowers, j ^'^riegated, 

( spotted. 
The fruits. 
The seeds. 

Variations in color are the most frequent of all 
modifications in cultivated plants. These depart- 
ures may be expected to arise under the influence 
of continued cultivation and repeated sowings ; 
and the variations must then be selected until 
they are fixed. 

9. Varieties ivitJwut color, or albinos. — Partial 
albinism, or A^ariegation, is as frequently observed 
in spontaneous plants as it is in cultivated ones. 
It usually occurs in the leaves only, but it is some- 



verlot's classification. 149 

times a feature of the entire plant. A variegated 
plant does not exist of which we do not know the 
non- variegated type. These variegated plants 
appear both from seeds and from bud-variations, 
and they are most surely propagated in the latter 
case. It has been said that when the albinism 
affects the margin of the leaf it is more likely to 
be transmitted than when it occupies the central 
part of the blade, but this generalization has many 
exceptions. Page 157. 

It is a curious fact that variegation and double- 
ness of flowers are generally antagonistic, for they 
do not appear in the same plant. One excludes 
the other. It is supposed by Morren [and gen- 
erally accepted] that doubling is the result of 
excessive vigor and that partial albinism comes 
of an enfeebling of the vital functions. 

Variegations sometimes disappear entirely and 
then, after two or three years, reaj)pear in the 
same individual. The first leaves of seedlings 
from variegated plants may be perfectly green, 
and the seedlings may afterAvards take on the varie- 
gated character. This behavior is well marked 
in some ferns. 

Complete albinism, or chlorosis, indicates a pro- 
found alteration in the tissues, and it is impossi- 
ble of propagation. This decoloration is most 
commonly a bud-variation. 

10. Double varieties^ or those distinguished hy 



150 BORROWED OPINIONS. 

the transformation of the stamens and pistils into 
petaloid organs — There are various degrees of 
doubling or duplication in flowers. The calyx 
and corolla alone may be duplicated, in which 
case the flower is still fertile. Sometimes the sta- 
mens only are transformed into petal-like organs, 
and the flower is then fertile if pollen is trans- 
ferred from another flower. Sometimes all the 
floral series — calyx, corolla, stamens, pistils — 
may be duplicated or transformed ; then we have 
a full (^pleine) flower, which is incapable of pro- 
ducing seeds or of fecundating another flower. 
[Annual plants, and others not propagated by 
buds and other asexual parts, which bear full 
double flowers, must be propagated by seeds taken 
from flowers which are nearly full double, but 
which bear a few seeds ; or, sometimes from a 
nearly single flower which is fertilized by pollen 
from a nearly full double flower. In these cases, 
it is unusual for all the seedlings to produce full 
double flowers.] 

A rich soil, a cultivation which produces a luxu- 
riant vegetation, are the conditions which gen- 
erally produce doubling in flowers. But we can 
repeat with De CandoUe, " That if we are gen- 
erally ignorant of the causes of the doubling of 
flowers, we also know that if we gather seeds 
from an individual with semi-double flowers, the 
plants which result have a greater tendency to pro- 



VERLOT's CLASSIFICATION". 151 

diice double flowers than seeds taken from simple 
flowers." 

Doubling may occur in all plants, whether an- 
nuals, biennials, herbaceous or woody perennials, 
and in all of them, when they are fertile, we can 
finally make them reproduce the character iden- 
tically. 

We must ahvays choose for seed-parents the 
individuals of which the flowers are very double, 
and exclude with the greatest care the single- 
flowered plants, which are the most fertile and 
the progeny of which quickly smother the progeny 
of the double flowers. 

11. Pi'oliferous varieties. — [These are varia- 
tions which are characterized by growths arising 
from unusual places, as one flower springing out 
of another flower, a branch or rosette growing out 
of a flower, an unusual production of bulbs or 
young plants from the root, bulbs from leaves or 
the fronds of ferns, and the like.] These forms 
are infrequent in cultivated plants and very rare 
amongst wild plants. They are generally asso- 
ciated with the fertility of the soil. The pro- 
liferous form of Papaver somniferum known as 
Papaver monstruosum, perpetuates itself per- 
fectly by seeds, but these variations are usually 
unstable. 

12. Varieties with conjoined parts (yarietes par 
soudures). — We know of a single example of this 



152 BORKOWED OPINIONS. 

monstrosity in ornamental plants : it is that of 
Papaver bracteatnm, in whicli the corolla has 
become monojDetalons by the growing together of 
the petals. This monstrosity (described and fig- 
nred in Revue ITorficole') is cnltivated by Vilmorin. 
They can propagate it only by cuttings. They 
have tried in vain to multiply it by seeds. [Simi- 
lar forms of other species are known.] 

12. Abortive varieties. — This type of monstros- 
ity, which constitutes one of the most interesting 
chapters in vegetable teratology, has been ob- 
served in all parts of the flower. They are mal- 
formations which have no interest from the point 
of view of ornament. [The petals, or other or- 
gans, sometimes almost entirely disappear in this 
type of variations.] 

11. Peloric va^rieties. — [Peloria is a name ap- 
plied by Limiceus to a form of the toad-flax, Lina- 
ria vulgaris, in which all of the five petals have 
spurs, while the normal form has only one petal 
spurred. The term is now applied generically to 
all similar regularity of structure in normally ir- 
regular flowers.] The causes which produce this 
transformation are not known, but aridity and dry- 
ness of the soil, and new conditions of vegetation, 
appear to favor its development. These mon- 
strosities, at least in linaria, are propagated easily 
by cuttings or buds, and Willdenow records an 
experiment in which they came true from seeds. 



veelot's classification. 153 

15. ClilorantUc varieties. — Here are included, 
in a general way and in lieu of a better name, all 
those transformations which render the flowers 
absolutely sterile, and transform them more or 
less completely into branches or leaf -like organs. 
They are purely bud-variations, and can be per- 
petuated only by cuttings, buds, or other asexual 
parts. 

16. Various or polymorplious varieties, compris- 
ing the following types : — 

thornless, 

spineless. 
Stems \ f astigiate, 

filiform, 

weeping, etc. 
C crisped, 

fasciated, 

bullate or blistered, 
[laciniate, etc. 



Leaves 



The various modifications originate both by 
seed-variation and bud-variation. 



II. Cakhiere's Account of Bud-Yabieties. 

The subject of bud- variations or sports never 
fails to interest the student, and however familiar 
he may be with these forms he never ceases to 



154 BOEROWED OPINIONS. 

wonder at them. I have taken pains, therefore, 
in addition to wliat I have already said upon the 
subject (see pages 28, 117), to translate almost 
bodily Carriere's account of bud-varieties (in Pro- 
duction et Fixation des VarietSs dans les Vege- 
taux)^ because, although written in 1865, it is 
the most extended list of bud-varieties which I 
know. The catalogue might be greatly extended 
by inserting the current varieties in commerce in 
this country, but the original list is sufficiently 
full for all purposes of illustration. Carriere's 
account now follows : — 

1. General Remarks upon Bud- Variation. 

Plants being composed of a certain number of 
elements disposed in a certain order, and, more- 
over, these elements, under the influence of organic 
laws, being able to separate or group themselves 
in different ways, it follows that the same plant 
can, upon its different parts, present characters 
and properties more or less different from those 
which it normally presents. It is this fact which 
constitutes that which in practice we call an acci- 
dent [or bud variety], either of dimorphism^ [of 
form] or of dichroism [of color] . 

1 French writers use the word accident in the sense in which 
we use bud-variation. The word dimorphism, used by Car- 
riere for one of the features of bud-variation, is now applied to 



caeriere's remarks on bud-variation. 155 

We refer to bud-variation the phenomenon, 
whose cause is unknown, which allows a bud on 
any part of the plant to develop a member whose 
form and appearance differ from those borne on 
other parts of the plant. Thus the common beech 
producing a branch with laciniate leaves, Podocar- 
pus Koraiana producing a branch whose ramifi- 
cations are whorled and spreading instead of being 
scattered, and Avhose leaves are distichous instead 
of being alternately disposed about the branches 
as they are normally, are examples of bud-varie- 
ties. 

Taken in its most absolute sense and considered 
in the sum of all its characters, bud- variation, aside 
from the details which it presents, can be divided 
into two sections : one which includes all the phe- 
nomena which are manifested suddenly, as in the 
case of the fern-leaved beech, the hemp-leaved 
rose, the English willow- leaved cherry, sour 
grapes with long seeds, etc. ; the other includes 
all slower transformations, as in the case of Rosa 
Eglanteria, tulips. Iris Xiphium, Viola Rotho- 
magensis, var. pallida, etc. Strictly, we could 
establish a third section to include all the trans- 
formations resulting from the age of the individ- 

different permanent and characteristic forms of individuals of 
the same species. It is most commonly observed in the different 
relative lengths of stamens and pistils. I have substituted other 
v^^ords for it in most places in the text. — L. H. B. 



156 BOEROWEU OPINIONS. 

nal, which are the consequences of its adultness. 
However, this hist series of phenomena is seen 
only in polymorplious species, wliich change in 
appearance, form, and nature when they grow old 
and especially when they bear fruit ; such are the 
ivies, Ficus stipulata or scandens, eucalyptus, etc. 
Horticulture often profits by this peculiar prop- 
erty of plants; multiplying separately the parts 
with the exceptional characters, it obtains individ- 
uals which present an appearance different from 
the plants from which they arise. [This dissimi- 
larity between young and mature individuals of 
the same species is well marked in some of the 
Coniferae, as the cedars and retinosporas.] 

In a general way, then, dimorphism refers to 
a different form on the same individual, whether 
the change be complete or partial. Dichroism is 
exactly analogous to it in essential points, only 
that it refers to color instead of to form. Thus, 
Flon's Pink [Dianthus semperflorens of gardens, 
introduced by M. Flon of Angers], which has red 
flowers, develo})ing a branch similar to tlie plant 
in aspect and form, but bearing white flowers, 
the ovate -leaved privet and the Japanese fusain 
[Euonymus Japonicus] producing buds giving 
rise to variegated leaves, white kidney-beans pro- 
ducing black ones, and vice versa, are examples of 
dichroism. 

Let us say that in bud- variation, less than any- 



OARPvIEUE ON BUD-VAKIATION. 157 

where else, we can do nothing towards obtaining 
or producing the variations. Bud-varieties most 
often spring up spontaneously, so to speak, and in 
this respect our work is purely passive, consisting 
in superintending these digressions or accidents 
in the endeavor to take advantage of them when 
they are presented. Let us state, also, that in 
these series of varieties we find a considerable 
diversity, either in the habit or aspect of the 
plants or in their foliage or flowers, or sometimes 
even in their fruits, and that we oftener find vari- 
egations than among plants which come from seeds. 
We ought to recall just here, — what we have 
said on the subject of plants issuing from seeds, — 
that variegations are the more constant the more 
completely they circumscribe the organs upon 
which they occur, whether upon the flowers or the 
leaves ; also, that when, on a plant whose variega- 
tions are disposed in stripes or bands, we find a 
part upon which they are disposed circularly, we 
can be almost certain that, if we detach and graft 
or make a cutting of this part, we shall preserve 
its new character. This phenomenon is very fre- 
quent in the camellias and especially in the azaleas. 
The greater part of the varieties of azalea which 
present these characters have had no other origin. ^ 

1 To preserve variegations, it is best to resort to graftage, 
generally speaking, as cuttings tend to produce individuals 
more vigorous, and which therefore tend to return to the green 



158 BORROWED OPINIONS. 

Certain species are miicli more disposed than 
others to produce these bud-varieties, either of 
dimorpliism or dichroism. We give an example 
from the Chinese chrysanthemum. About 1836, 
the horticultural establishment of Fromont re- 
ceived from England three varieties of this 
chrysanthemum; one had the floAvers red, one 
variegated, and one Avhite flesh-colored. Planted 
in the open air, the following year we saw the 
three varieties on one plant, which seems to 
show that these three varieties were only sports 
from a common form. A phenomenon analogous 
to the preceding, and which, like it, concerns the 
Chinese chrysanthemum, was shown at the Mu- 
seum ^ in 1856 upon a variety called Surprise. 
This, which bore flowers scarcely rose flesh-col- 
ored, produced, on one of its branches, flowers of 
a deep rose-like. Cuttings having been made, 
it has preserved all its characters, and to-day it 
is still one of the most beautiful of the section. 
We call it Gain du Museum. In 1862, upon this 
same Gain du Museum, a branch developed which 
bore flowers perfectly white, of almost the same 
size and form as those of the type; then upon dif- 

color, or even to the normal form, if the variety differs also in 
form. We must select the parts, in perpetuating variegations, 
in which the variegation is very pronounced, although we must 
exercise care that the variegation be not too intense, else the 
offspring will be weak and poor. — Caeriere. (See page 149.) 
1 Museum d'Histoire Naturelle de Paris. 



CAEPvIERE ON BUD-VAEIATION. 159 

ferent branches beside it were found others bear- 
ing flowers half red, half white. In making cut- 
tings from these tAVO kinds of branches, we would 
then obtain from the Surprise still other varieties. 
Let us look at the variety Sophie. This, which 
has dirty white flowers very slightly tinged with 
red, with yellow centre, has produced, by bud- 
variation, a plant knoAvn as Trophee. The latter, 
which has flowers of a rose-lilac-violet, bears some 
resemblance to the Gain du JMuseum. There 
were also upon the same branch, but on different 
twigs, flowers similar to those borne by the varie- 
ties Trophee and Sophie. These new flowers 
were flat and had narrow and imbricated petals, 
wliilst the Trophee has convex flowers, large and 
slightly serrate petals. The Madame Eichard 
chrysanthemum, of which the flowers are whitish 
very lightly bordered with rose, has produced on 
one of its branches violet flowers stronger than 
those of the plant from wliich it sprung ; the 
petals are also larger and more imbricated. In 
1863 Ave observed on certain varieties of chrysan- 
themum the following sports: the variety called 
Cedo nulli, Avith double Avliite floAvers very lightly 
rose, produced a brancli Avhich bore flowers much 
larger and much more spreading than those of 
Cedo nulli. The Argentine, Avith small AAdiite 
floAvers, pompon-form, gave a branch more vigor- 
ous than itself, whose spreading, very large flow- 



160 BOEROWED OPINIONS. 

ers, of a beautiful yellow, resembled to a certain 
extent those of the large-flowered chrysanthemum, 
a fact which tends to show that from the pompons 
to the large-flowered sorts there is but a step. In 
1864 we saw upon a stem of the Yesta (a pompon 
chrysanthemum which has white flowers) several 
branches which bore flowers entirely deep yellow. 
The dimensions, as well as the form of the 
flowers, were the same. 

Varieties obtained by bud-variation are very 
numerous. There is not a genus among those 
which comprise a number of species Avhich has 
not produced them. Although we shall mention, 
farther on, a certain number of these bud-varie- 
ties, adding some observations, there are some 
which, in our opinion, are so interesting that, by 
anticipation, we ought to speak of them here. 
One of them relates to a kind of pink which is 
known in commerce as Flon's pink. This Flon's 
pink, which is closely related to those which we 
call Spanish pink, Badin pink, etc., has flowers 
very deep red, almost double, so that it does not 
produce seeds, and we are obliged to multiply it 
by cuttings. Nevertheless, it has already given, 
by bud-variation, several varieties, of which the 
most remarkable, a very beautiful white, was de- 
veloped in 1858. Since that time this variety 
has been maintained with all its characters. Ob- 
tained by M. Pare, horticulturist at Paris, this 



CAREIEKE OK ROSE SPOETS. 161 

variety has been called INIarie Pare, for one of 
the children of the originator. Other varieties, 
presenting colors different from that of which we 
have spoken, have been develoj^ed from Flon's 
pink by M. Pare. [The pinks are fertile in bud- 
varieties, particularly the carnation. Many of 
the carnations which are now well known to com- 
mercial growers first appeared as sports. The 
Portia, which is a deep self -red, frequently sports, 
sometimes into almost pure white.] 

The genus which, probably, has produced the 
most examples of this nature is the Rose. The 
examples are so very interesting that Ave cannot 
resist the temptation to say something in detail 
concerning them. We will cite several remark- 
able examples, connnencing with those which 
have sprung from the Hundred-leaved Rose [Pro- 
vence rose, Rosa centifolia]. The bud-varieties 
which have issued from this rose can be arranged 
in two series : one which includes all individuals 
which are but little removed from the type, which 
differ from it only in color or form, either of the 
flowers or sometimes of the leaves, and comprise 
the ordinary Hundred-leaved roses; the other 
series includes individuals possessing the charac- 
ters of the first series, but which, in addition, are 
provided with small bracts or glandular hairs 
which give the name "Moss-rose." Bud-varieties 
produced by Rosa centifolia : — 

M 



162 BOKROWED OPINIONS. 

A. Ordinary Hundred-leaved roses. 

I. Flowers more or less larofe. 

Cahhage-leaved or lettuce-leaved R. cen- 

tifolia. 
Celery-leaved. 
Ane^yione. 
Nancy, 
Peintres. 

Flore magno,, or Foliaceous. 
Apetalous, 
Unique white. 
Unique variegated. 

II. Flowers small. — Pompons. 

Burgogne pompon. 
White pompon. 
Bordeaux pompon. 
Kijigston pompon. 

B. Moss-roses. 

I. Flowers more or less large. 

Ordinary. 

Oristata. 

White-floivered 

Variegated. 

Sage-leaved. 

Unique Provence. 

Zoe^ or Mousseuse partout. 

II. Flowers small. — Pompons. 

Pompon. 



CAREIERE ON ROSE SPOKTS. 163 

One must not suppose that all the moss-roses 
which he meets with to-day in commerce are the 
result of bud-variation. The larger part, on the 
contrary, come from seeds. The moss-rose is 
nearly a race. From seeds taken from the moss- 
rose, we have obtained a certain number of 
individuals which have preserved the general 
characters of the plants from which they came ; 
they are more or less "mossy." Let us state, 
however, that this ''mossy" character is not pecu- 
liar to any section of roses, but that we find it 
in most garden species, as the hybrid remontants, 
rose~of-four-seasons, etc. The fact of the repro- 
duction of the " mossiness " of roses by seeds, 
proves again, what we have asserted several times, 
that everything in a plant tends to reproduce 
itself, that the peculiarities, properties, monstrosi- 
ties even, may become hereditary. 

The Zoe moss-rose is one of the most remark- 
able bud-varieties which has been produced by 
Rosa centifolia. This variety, instead of being 
" mossy " only upon the peduncle or calyx, as 
most of the other varieties of this group are, 
is "mossy" on all its parts, whence the name 
Mousseuse partout^ [" mossy every where "] . This 
variety was produced again in 1864, at M. Ja- 
main's, horticulturist, Paris, where Ave followed 
the development of it. We also learned that at 
this place, in two beds planted with ordinary 



164 BORROWED OPINIONS. 

moss-roses, beside the Zoe, there were several 
stems which tended likewise to modify them- 
selves, some in their leaves, others in their 
flowers. 

We mnst remark that it often happens that 
certain individuals of bud-varieties return, on 
some one of their parts, to the type from which 
they came. Thus, on a moss-rose from R. cen- 
tifolia, we have seen a branch of the ordinary 
Hundred-leaved rose. We should observe, how- 
ever, that most usually the parts which seem to 
return to the type present, notwithstanding, differ- 
ences from it. There has been a step in advance, 
and it is contrary to nature to retrace completely. 

The Rose du Roi, known by nearly every one, 
has produced the following six bud- varieties : — 

1. Bernard Perpetual. This rose has the 
branches more slender than those of the parent; 
its flowers and leaves are also smaller. Its pom- 
pon flowers are very pretty, with a rose-color very 
much brighter than that of the Rose du Roi. 

2. Long-peduncled Rose du Roi. This has 
branches much longer than those of the type ; 
the internodes are more distant, and the peduncles 
are also longer. It is only a sort of degeneration. 

3. Madame Tellier. Very similar to the last, 
being distinguished only by its flowers, which are 
less colored, possessing a very bright rose flesh- 
color. 



CAERIERE ON ROSE SPORTS. 165 

4. Mosrador. This rose differs from Rose du 
Roi by its stronger flowers, of a more vivid, deeper 
red ; its branches more colored, permitting it to 
be distinguished even in winter. Horticulturists 
do not like this variety, because it is hard to 
force, and because it passes very quickly to a 
dirty violet. 

5. Capitaine Renard, or Variegated Rose du 
Roi. This variety differs from Madame Tellier 
by its flowers being variegated or ribboned with 
white. It was found at Orleans by M. Desfosse- 
Thuillier. 

6. Coelina Dubos. Found by M. Dubos, hor- 
ticulturist at Pierrefitte, near Saint-Denis, upon 
Rose du Roi. It has the branches more slender 
and the leaves a little smaller than the parent ; 
its flowers, very similar in form to those of the 
type, are white, slightly flesh-colored. 

The Rose de la Reine has x3roduced two sjDorts : 
one. Belle Normande, whose flowers, rose flesh- 
colored, recall those of Souvenir de la Malmaison; 
the other, Madame Cambel of Isly, or Triomphe 
de Valenciennes, which differs from the parent 
only in its marbled-variegated flowers. 

The Duchesse de Cambaceres rose^ which has 
uni-colored, deep rose flowers, has produced by 
bud-variation Belle de Printemps, which has rose 
flowers marbled with brown. 

The Baronne Prevost has produced, to our 



166 BORROWED OPINIONS. 

knowledge, five varieties, two of which have 
variegated flowers and one marbled. One of the 
two variegated varieties, Madame Desiree Giraud, 
was found at the place of M. Desire Girand at 
Marly, near Valenciennes. It is not vigorous. 
The second variety, Panachee d' Orleans, which 
was observed for the flrst time at Orleans, is 
very vigorous. Its branches are more slender 
than those of Baronne Prevost, and the very 
smooth and shiny bark has few prickles. In 
short, its branches recall those of Cuisse de 
Nymphe. It sometimes happens that this variety 
produces large branches, vigorous and very thorny, 
but less so than those of Baronne Prevost ; its 
flowers also resemble the type more closely. It is 
an intermediate produced by the single matter of 
vegetation. The Baronne Prevost marbre dif- 
fers from the type only in its flowers, which are 
marbled with brown. Another variety, placed 
in the trade by M. Pierre Oger, horticulturist 
at Caen, differs from the type only in the color 
of the flowers, which are very much paler. The 
fifth sport produced by the Baronne Prevost is 
more recent. We observed it first in 1864, at 
Vitry-sur-Seine, in a garden under the care of 
M. Lachaume. We called it Madame Lachaume. 
It differs from the type by its branches being a 
little less thorny, but especially by its inflores- 
cence, which, long-paniculate, very mucli branched. 



CAKRIEEE ON KOSE SPOETS. 167 

recalls that of certain Noisettes. The flower, also, 
is a little weaker than that of the type. But a 
very remarkable fact is that the hip, instead of 
being very regularly attenuated at its base and 
becoming confounded with the peduncle, as in 
Baronne Prevost, is abruptl}^ and slightly in- 
flated, then contracted, and inflated again near 
the summit. The peduncles are also much more 
slender and longer than those of the parent. 

The Duchesse d' Orleans, whose flowers are 
violet-rose, produced by bud- variation, in 1858, a 
variety known as Soeur des Anges. This variety 
difl'ers from its parent particularly in the color of 
the flowers, which is pale flesh-rose, like that of 
the flowers of Souvenir de la Malmaison. 

The rose called Quatre-Saisons has produced 
the f olloAving sports : — 

1. White Moss, or de Thionville. This was 
first observed at Thionville about 1835. It dif- 
fers from the type by its branches being more 
slender and supplied Avith hispid, glandular hairs. 
Its light green leaves are also softer to the touch 
and slightly tomentose. Its flowers are pure 
white. Sometimes it produces strong branches 
which bear rose-colored flowers. In this latter 
condition it is the ordinary Quatre-Saisons, a fact 
observed by M. Duval of ^lontmorency, later by 
M. Victor Verdier, Paris, and recently (1861) at 
the Museum. 



168 BOKEOAYED OPINIONS. 

2. Quatre-Saisons pompon. 

3. AVhite. 

The Provence roses have likewise produced a 

number of bud-varieties. Among the best known 

are : — 

Pompon Saint-Frangois. 

Pompon Saint-Jacques. 

Camaieu. 

Panache semi-double. 

Tricolore de Flandre. 

The last variety, Avhich appeared in Belgium 
some years ago, is remarkable for its variegated 
flowers ; it is a slender grower, although it comes 
from a very vigorous variety. It sometimes re- 
turns to the type. The variety Camaieu is remark- 
able for its striped flowers, very pretty, and al- 
most unique in the genus. Its wood is meagre 
and its leaflets are toothed. 

In the Damask roses, which are sorts of Quatre- 
Saisons roses, not remontants, we consider as bud- 
varieties the three f olloAving : — 

Damask York and Lancaster. 
Damask with blistered leaves. 

The ordinary Bengal rose has sported into the 
Bengale a bois strie [striped-stemmed Bengal]. 
The branches are often almost completely yellow. 

A very curious sport of the rose is the plant 
which we have called Rosier a feuilles de Chanvre 



BUD-VAKIATION IK THE EOSE. 169 

[hemp-leaved rose] . By its flowers and especially 
by its leaves, this variety differs considerably from 
Rosa alba, from which it comes. Its leaflets are 
hooded, long and narrow, and very coarsely den- 
tate-serrate, sometimes as if gnawed on the edges, 
strongly nerved, of a dark green, rugose-scabrous. 
It happens sometimes, also, that its leaves are 
opposite upon certain branches. The flowers of 
this variety are smaller than those of Rosa alba, 
often irregular, and somewhat monstrous, and 
always sterile. [Probably no plants are so prolific 
of bud-varieties as the roses. Every gardener of 
experience has observed the fact. The follow- 
ing experiences of a single horticulturist (Ernest 
Walker, New Albany, Indiana), with one rose, 
illustrate this fact admirably. "I have had a 
number of sports of the Perle des Jardins rose," 
he writes me, " in our greenhouses. The first one 
was a double silvery pink with a short bud, and a 
very double, somewhat quartered flower. The 
stock of this I sold, as a new variety, for fifty 
dollars. The next sport was a white Perle. [The 
Perle is a golden-yellow rose.] I sold a plant of 
Perle to a local customer, who afterwards com- 
plained that it was not true to name, because the 
flower Avas white. She took it to be Cornelia 
Cook. I went to see the rose, and found a Perle 
rose in everything but color. I secured the jjlant, 
and was intending to introduce it, when, within 



170 BOREOWED OPINIONS. 

a few months, I heard that Nanz & Neuner, of 
Louisville, Kentucky, had one, and that a London 
firm had another ; and later I found that one had 
originated in Germany. Another sport of Perle 
was a single rose, like Isabella Sprunt. Another 
was like a Madame Falcot. At another time a 
whole branch sported into a form with a long, 
slender bud (about two inches long and five- 
eighths inch in diameter), with only two calyx 
lobes, and only two petals, — Avhich were very 
broad, — in each cycle or series. This sport was 
really a monstrosity, and I could not propagate 
it."] 

The so-called ornamental plants are not the 
only ones which present these examples of hetero- 
morphism. Fruit trees furnish very remarkable 
examples. We will cite some cases, beginning 
with those furnished by the cherry called Anglais 
hatif [Early English]. The most curious sport 
given us by this cherry is that which we call 
Cerisier Anglais heterophylle or a feuilles de 
saule [heterophyllous or willow-leaved English 
cherry] . Tliis is the history of the sport : 
Upon a young tree whose parts are normal, we 
see, sometimes suddenly and without apparent 
cause, a vigorous bud develop, which bud, instead 
of producing leaves of the ordinary form, bears 
those which are very long and narrow, often 
somewhat falcate, and often irregularlv erose. 



CAKRIERE OK CHEllllY SPOUTS. 171 

Grafted, this variety presents very singular pecu- 
liarities, as follows : so long as it preserves its 
exceptional characters the plant does not flourish, 
but as it constantly tends to lose them we observe 
that when the leaves have almost returned to the 
normal form the trees flourish and bear. Never- 
theless, this variety never resumes identically the 
characters of the type from which it came. Its 
aspect is always distinct. The tree is never 
fertile, and its fruit also differs from that of 
the Early English. The young shoots preserve 
their accidental character, and each year the leaves 
which it develops are nearly identical to those 
which the variety produced when it was first 
developed. 

This variety is not the only one which is pre- 
sented by the Early English. Thus, when the 
trees are old, it frequently happens that we find 
on the same individual three kinds of fruits, dis- 
tinct in their times of maturing. There is, first, 
the Early English, whose fruits become black ; 
the Late English, whose fruits, of a beautiful 
deep red, shining as if varnished, ripen later. 
Finally, we nearly always find another variety, 
very late, whose fruits, a little smaller, are still 
entirely green when the other two have been 
gathered a long time. In these three sports, the 
differences are shown only on the fruits. The 
Indule oherry is also only a sport from the Early 



172 BOREOWED OPINIONS. 

English. It is distinguislied by its foliage and 
earliness. The Early English cherry is not the 
only one which furnishes bud- varieties pertaining 
to the fruits. We find analogous examples in 
the May Duke, Cherry Duke, and Reine Hor- 
tense. These varieties, indeed, have produced 
on different branches of the same individual sub- 
varieties whose fruits ripened a fortnight later 
than normally. Grafted, each of these sub- 
varieties preserves its accidental character. 

A phenomenon analogous to the preceding ones 
is shown each year at the Museum upon an or- 
dinary double-flowered cherry. The tree upon 
which this anomaly was developed is nearly four- 
teen inches in diameter, is grafted on the Sainte- 
Lucie about twenty-seven inches above the ground. 
Above the junction the stein is naked for about six 
and a half feet. At this height is a large branch, 
which every year is covered with extremely double 
flowers, whilst the flowers of other branches, ex- 
panding very much later, are scarcely half double, 
and yield fruits. 

The Coe violette plum is an example of dichro- 
ism. It is a bud-variety which was produced on 
the White-fruited Coe, and which, grafted, is 
maintained with all the characters which it pre- 
sented at the time of its appearing. We have 
very often observed upon the Damas de Tours 
plum an instance almost the same as the j^i^eced- 



CAllKIEEE ON SPOETS OF FEUITS. 173 

insf. On the same tree there were branches 
which bore fruits different in form and color, and 
differing a fortnight in time of maturing. Thus, 
while the fruits of the type are very large, length- 
ened, of a deep red color which recalls the Pond 
Seedling, marked only on one side by a very 
slight furrow, the fruits of the later sub-variety 
are a little smaller, and their form is that of the 
ordinary Reine Claude ; they are of an herba- 
ceous green, which passes more or less into a very 
clear red ; the stem, arched, swollen at the base, 
is inserted in a cavity quite large by the widening 
of the furrow, whilst the stem of the typical fruits 
is erect, little or not at all swollen, inserted in a 
very small cavity placed almost on the surface of 
the fruit. 

Another plum, the Prunier Puget, presents the 
following peculiarities : Upon the same branch it 
very frequently happens that there are fruits of 
a violet-red, dotted or striped with red-green. 
We find some, also, which j)i'esent all the inter- 
mediate tints and others which are almost uni- 
colored. By multiplying them separately, there 
may be a chance to establish these varieties and 
to obtain several from one tree. 

We have seen on a red-fruited currant bush a 
branch which bore fruits as white as those of the 
Hollande a fruits blancs [White Dutch]. 

The fact of the nectarine coming suddenly from 



174 BORROWED OPINIONS. 

a peach can no longer be doubted. Recent ex- 
amples have come to support the experiments of 
certain authors, notably SieuUe. 

Two other similar examples, of which we ought 
to speak, are furnished by two varieties of Chasse- 
las grapes, one known as Chasselas panache [Va- 
riegated Chasselas] and Chasselas Suisse [Swiss 
Chasselas]. Both appear to have come from a va- 
riety with black fruits, the color which predomi- 
nates in them. These are the peculiarities which 
they present : almost all the bunches bear some 
fruits more or less variegated or striped, white 
in Chasselas Suisse, red in Chasselas panache. 
But it happens frequently that the elements are 
separated and that we have then, upon different 
shoots, sometimes upon the same shoot, bunches 
of grapes of different color, almost entirely white 
if they belong to the Chasselas Suisse, and red if 
they belong to the Chasselas panache. One of 
the varieties is only a modification of the other, 
which is itself only a modification of some other. 

The pear Saint-Germain gris, whose deep gray 
fruits are very different in appearance from those 
of the ordinary Saint-Germain, is a bud-variety 
which was produced upon a branch of the latter, 
and which, multiplied by grafting, is maintained 
in all its characters. A similar variety was pro- 
duced on the Messire-Jean, so that at present we 
possess in the gardens a Messire-Jean gris, and 



CARRIERE ON SPORTS OF FRUITS. 175 

a Messire-Jean jaune [gray and yellow Messire- 
Jean]. To these examples we will add two other 
analogous ones, which were recorded in the Bul- 
letin de V Academie des /Sciences^ xxxiv., meeting 
of Maj 17th. One, given by M. Bureau de la 
Malle, refers to the Bon Chretien pear, which 
produced sometimes typical fruits and at others 
" of a form entirely different and unknown." The 
other example, cited by M. Mourriere, professor 
at Bernay, has reference to an apple which, on the 
same branches, produced fruits which had the 
appearance of a Reinette rousse and others which 
resembled a kind of Reinette du Canada. The 
latter is smooth, punctated, and often of a bright 
red upon one side. [The recent experiments 
of Waite, in this country, respecting the imme- 
diate influence of pollen, raise the question if 
some of these minor variations in form of the 
pear fruit may not have arisen from vagaries of 
pollination.] 

The various examples which we have cited are 
common to a very large number of plants, among 
which we will cite the banana and sugar-cane. 
Indeed, although these plants do not produce 
seeds, we find in each species a large number of 
varieties which are very distinct in vigor, aspect, 
habit, and in the banana in form, size, and quality 
of fruit. All these varieties are produced by 
bud-variation. These remarks can be applied to 



176 BOEROWED OPINIONS. 

other monocotyledonous plants, as Arundo, Pha- 
laris, Bamboos, Dracaena, Yucca, etc. 

[Carriere cites the different shapes and colors 
of beans in the same pod as examples of bud- 
variation, but it is a question if these differences 
are not determined in the seed of the previous 
year. At all events, since there is only a single 
year in the life of the bean, we prefer to ascribe 
variations in it to the generation of the parents 
from which it has just sprung. There is no pre- 
vious year's growth of the same individual Avith 
which to compare variations and to ascertain if 
they are bud-departures from the type. Page 118.] 

2. Lht of Bud-varieties?- 

After having sought to present certain examples 
of bud- variation which, by their importance, seem 
to be sufficient to fix the attention, we will con- 
tinue by the enumeration of a certain number of 
others, without, however, entering into details for 
each one of them. Sometimes we shall give only 
the name of the variety. If, however, they pre- 
sent particular interest, either in a practical or 
scientific point of view, we shall dwell upon them 
more at length, considering either their origins or 
peculiarities. [The garden names of the plants 

1 The student should also consult Darwin's "Animals and 
Plants under Domestication," 



caeriere's list of bud-varieties. 177 

are given essentially as they stand in the original, 
for, as the purpose of this list is to acquaint hor- 
ticulturists with the nature and frequency of bud- 
variations, I have considered it unnecessary to 
make any particular attempt to revise the nomen- 
clature. The names are familiar, and, therefore, 
useful as they stand.] 

It would have been easy to extend this enumera- 
tion of examples of bud-variation. We have not 
thought it necessary because, aside from leading 
us too far, the real interest of the subject Avould 
gain nothing by it. We have, then, thought it 
our duty to put limits upon a subject which has 
no limits. 

Acer eriocarpum, fasciatum. 

Very remarkable for its much fasciated branches. 
This variety showed itself at the Museum in 1857 
upon a seedling which, during the first two years, 
presented nothing abnormal. In the third year, 
when the tree had been cut back, the sport 
appeared, since wdiich time it has maintained itself 
with all its characters. This variety is to A. 
eriocarpum what the variety montrosa is to Sam- 
bucus nigra. 

Acorus gramineus, variegata.^ 

1 When a name is not followed by remarks, the reader is to 
understand that it represents a known variety and that the 
name of the species indicates the origin of the variety. — L. H. B. 

N 



178 BOREOWED OPINIONS. 

JEsculus rubicuncla, variegata. 

[^^sculus Hippocastanuin, double - flowered. 
Upon a well-known Horse Chestnut tree in the 
environs of Geneva the owner, in 1822 or 1823, 
detected a single branch bearing double flowers. 
This still continues to bear double flowers and 
grafts from it do the same. It is thought to be 
the original of all the doubled-flowered Horse 
Chestnuts in the world. — A. De Candolle hi Acad. 
Sci.^ Paris, 1875, quoted by Asa Gray, Sillimans 
Journ. 3d ser. x. 238] . 

Agathpea amelloides, variegata. 
Ageratum Mexicanum, nanum. 

This plant, which is now used to so much ad- 
vantage for borders, is the product of a branch 
which developed accidentally from A. Mexicanum. 
Its heads are almost sessile and a little irregular, 
borne so close to the leaves as to make the plant 
undesirable from some points of view. The type 
plants, on the contrary, Avhich are very much 
larger, have the heads large and regular and raised 
on long peduncles. 

Ageratum Mexicanum, intermedium. 

This variety, which is a bud -variety of sec- 
ond degree, that is, a sport from a sport (from 
the variety nanum), is intermediate. The plants 
are very floriferous. Their heads are also better 



caeriere's list of bud- varieties. 179 

than those of the type, and as they are borne 
upon longer peduncles, the plants are not only 
suitable for garden ornament but for cut flowers. 
The dimensions of this variety are intermediate 
between the last variety and the specific type. 

Ageratum Mexicanum, variegatum. 

This differs little from the type except by its 
leaves being variegated with yellowish-white on 
the margins. Its inflorescence is, however, a little 
more slender and its heads are smaller. In gen- 
eral, the plant is "leggy," weak. 

Almond with variegated leaves. 

Leaves bordered and made satin-like with white ; 
vegetation delicate. It sometimes returns to the 
type. 

Anemone Japonica, Honorine Jobert. 

Very vigorous and very beautiful. This vari- 
ety, of which the flower is white, is a bud-variety 
from the so-called A. hybrida or A. elegans, 
which was obtained in England by M. Gordon by 
crossing A. Japonica with A. vitifolia. The va- 
riety was produced some years ago at M. Jobert's, 
amateur at Verdun. 

Apricot with variegated leaves. 



180 BORROWED OPINIONS. 

Aralia trifoliata, Cookii. 

This plant has its leaves, in general, simple, 
long, and narrow. 

Arunclo Donax, variegata argentea, and A. Donax, 

variegata aurea. 

These varieties differ from the type by the 
leaves being bordered with white in the first, 
and with yellow in the second. They are much 
more delicate than the type. 

Aspidistra elatior, variegata. 

Aster bicolor. 

This plant, which we believe not to be a dis- 
tinct species but simply a dwarf -form, very prob- 
ably a bud-variety of A. versicolor, produced at 
the Museum in 1856, upon one of its stems, a 
vigorous bud which presents all the characters of 
A. versicolor except that it is a little smaller. 
This variety, to which we have given the vari- 
etal name iVIajor, has preserved all its characters 
when multiplied by root-cuttings, and to-day is 
still one of the most beautiful perennial plants. 

Azalea Indica, Dieudonne Spae. 

Flowers salmon, margined with white. It is 
a sport from A. formosa, I very, which has rose 
flowers. 



carriere's list of bud-varieties. 181 

Azalea Iiidica, Beaute de T Europe. 

This variety has flowers white at tlie base, 
variegated with red. It is a sport from A. deli- 
cata, which has deep sahiion flowers. 

Azalea Iiidica, Criterion. 

Flowers deep rose bordered with wdiite. This 
is a sport from A. Iveriana, which has flowers 
white, striped with rose. 

Azalea Indica, alba rosea. 

Flowers rose, slightly bordered with white. A 
bud- variety from A. Iveriana. 

Azalea Indica, exquisita grandiflora. 

Flowers deep rose bordered with white. It is 
a bud- variety from A. alba perfecta, which has 
flowers white, very lightly striped with rose. 

Buxus Balearica, cucuUata. 

This bud- variety of B. Balearica differs from 
its parent by its smaller leaves, which are very 
strongly convex, and rounded in the middle. 

Buxus sempervirens, argentea. 
Buxus sempervirens, aurea. 
Buxus sempervirens, marginata. 

All these varieties are distinguished from the 
type by their leaves being variegated or bordered 
Avith either white or yellow. 



182 BORROWED OPINIONS. 

Camellia Japonica, Comte de Paris. 

This variety, wliicli lias strongly striped rose- 
flesh-colored flowers, is a sport from the Duchesse 
d'Orleans, which bears white striped flowers. This 
variety is not only much more vigorous than its 
parent, but it has the merit of fully expanding its 
flowers, while the buds of the Duchesse d'Orleans 
almost always fall before opening. 

Camellia Japonica, Montironi rosea. 

This plant, whose flowers are entirely rose, is 
a sport from the Montironi, which has white, very 
lightly striped flowers. 

Camellia Japonica, Giardino Franchetti. 

Flowers deep rose, bordered Avith white. It is 
an offshoot from C. Targioni, Avhich has white 
flowers lightly striped with rose. 

Camellia Japonica, Conitesse Woronzoff. 

This variety, which has delicate rose flowers, is 
a sport from C. centifolia alba, whose flowers 
are pure white. 

Camellia Japonica, Giardino Schmitz. 

Flowers delicate rose-color. It is a bud-variety 
from the Elisa Centurion, Avhich bears very lightly 
rose-striped Avhite flowers. 



carriere's list of bud-varieties. 183 

Camellia Japonica, Imperatrice Eugenie. 

Flowers rose-flesh-colored. A bud-variety from 
Montironi, whose flowers are very striped with 
rose. 

Camellia Japonica, Paolina Armari. 

Flowers deep rose. Bud- variety from Miss 
Abby Wilder, which has white, lightly rose-striped 
flowers. 

Camellia Japonica, Princesse Aldrovandi. 

Flowers rose, bordered with white. Sport from 
Teutonia, which bears flowers white, rose -striped. 

Camellia Japonica, Bicolor de la Reine. 

Flowers rose, bordered with white. It is a 
sport from de la Reine, whose flowers are white, 
lightly striped with rose. 

Last year we saw upon a camellia with rose 
flowers, some branches bearing flowers completely 
white. 

Cephalotaxus pedunculata, fastigiata. 

This variety, which has been described and 
figured as being a species of Podocarpus (P. 
Koraiana), is an example of bud-variation. We 
had proof of this statement at the INIuseum in 
1863. Having made cuttings from a certain num- 
ber of branches of the so-called Podocarpus, one 



184 BORROWED OPINIONS. 

of tliem, instead of producing simple and scat- 
tered, strictly erect brandies bearing scattered 
leaves, produced wliorled, horizontal branches 
bearing distichous leaves. The variety fastigiata 
is to C. pedunculata what Taxus baccata, fastigi- 
ata, is to T. baccata. 

Cereus Peruvianus, monstrosus. 
Sometimes returns to the type. 

Clematis bicolor or Sieboldii. 

This plant, of which the flowers, violet inside, 
are almost double from the transformations of the 
stamens, is a sport from C. florida, which has 
single greenish- white flowers. We have several 
times had occasion to ascertain that such is the 
origin of this clematis. 

The variety known as C. bicolor, flore pleno, 
which we sometimes call Atragene Americana, 
so remarkable for its enormous greenish-white 
flowers, is a direct sport from C. bicolor, conse- 
quently a bud-variety of the second degree from 
C. florida, a fact which we have been able to 
verify again this year. On a plant of C. bicolor, 
planted in the open air, there is developed, almost 
from the base, a branch which bore flowers en- 
tirely full, monstrous, yellowish-green, so that the 
two bud- varieties — C. bicolor and its variety flore 
pleno — were united upon the same individual. 



carriere's list of bud- varieties. 185 

Clematis, Helena monstrosa. 

This plant is none other than C. Helena which, 
by bud-variation, is transformed and has become 
double flowered. This example is analogous to 
that which is produced by C. bicolor. 

Cheiranthus Cheiri, variegata flore pleno. 

Sport from the double-flowered yellow gilly- 
flower of the walls. 

Cherry. See page 170. 

Cornus sanguinea, variegata. 

Cornus Mas, variegata. 

Cytisus Adami. 

Whatever may be the origin of this plant, 
whether a hybrid, as is generally believed, or a 
peculiar form, Ave propose here to say nothing 
concerning it beyond a verification of its peculiar- 
ities. It develops very frequently and normally, 
so to speak, some branches of C. Laburnum 
and others belonging to C. purpureus. When 
we graft separately these two kinds of branches, 
these species remain invariable, although the 
g'rafts were taken from C. Adami. 



i=> 



Dactylis glomerata, variegata. 



186 BORROWED OPINIONS. 

Ecliinocactus multiplex, cristata. 

This variety, instead of having a regular, 
lengthened, melon-like stem, forms a thick mass 
which extends itself into little fan - shaped 
bunches, and instead of longitudinal furrows, 
large and deep, and separated by protuberances 
upon which are borne long, very rigid spines 
(about three - fourths to one and two -fifths 
inches) ; the variety has only very slight fur- 
rows or kind of folds disposed transversely to 
the direction of the fasciation, consequently in 
a contrary direction to those which are presented 
by the type, and uj^on the borders are spurs 
(about two-fifths inch long) disposed in stars. 
In a word, the variety is entirely different from 
its parent. 

Elseagnus reflexa, variegata argentea and varie- 
gata aurea. 

These two varieties differ from the type in 
having their leaves bordered, respectively, with 
white or yellow. 

Elgeagnus pungens, variegata. 

Euonymus Japonica, argentea and aurea. 

These, especially aurea, return sometimes to the 
type. 



carrieke's list of bud-varieties. 187 

Euonymus Japonica, flavicla. 

Tliis plant, which developed upon a type plant 
with green leaves in 1862, is distinguished by its 
leaves being bordered with yellowish-green, some- 
times with nearly white. It is vigorous. 

Euonymus Japonica, fasciata. 

Very remarkable for its much fasciated branches. 
This variety appeared at the Museum in 1864, upon 
a typical E. Japonica. 

Euonymus Japonica, calamistrata. 

This sprung from the variety argentea, from 
which it differs in its more slender parts. Its 
leaves are smaller and crisped as if erose. 

E. Japonica has also produced many other bud- 
varieties, Avhich differ in variegation, or sometimes 
even by the form of the leaves. It is more than 
probable that the various varieties which have been 
introduced recently from Japan are bud- varieties. 

Fagus sylvatica, fern-leaved. 

This variety once presented the following 
peculiarity : Having grafted it upon the com- 
mon beech, the branches developed from each 
side of the stem almost distichously. All those 
upon one side bore leaves similar to those of the 
common beech, whilst those upon the other side 
bore only laciniated leaves. 



188 BORROWED OPINIONS. 

Ficus scandens, microphylla. 

This variety, which we sometimes meet in com- 
merce under the name of F. buxifolia, is a bud- 
variety which aj^peared in 1856 at the Botanic 
Garden of Orleans upon a plant of F. scandens 
grown in a greenhouse. Its leaves are very small, 
somewhat suborbicular and marked with brown. 
This variety is preserved in all its characters, 
both upon the original plant and in all the multi- 
plications which have been made of it. 

Fontanesia phyllireoides, variegata. 

This very pretty variety appeared at the 
Museum in 1854. Since its appearing, this vari- 
ety has not varied. Its branches, of a yellowish- 
green, are slender, and the leaves are deeply 
bordered with yellowish- white. 

Fraxinus Americana, variegata. 

Fraxinus excelsior, jaspidea. 

This variety is distinguished by its bark being 
striped or slightly ribboned with yellow. 

Fraxinus excelsior, variegata. 

The common ash has produced several sports 
which are marked by the variegation of their 
leaves. This one has yellow and white disposed 
in bands and bordering the leaves, or sometimes 



carriehe's list of bud- varieties. 189 

in spots upon all parts of the blade, as upon the 
leaves of Aucuba, for example ; hence the various 
names, argentea, aurea, striata, maculata, aucubse- 
folia, etc. 

Gardenia radicans, variegata. 

In this instance the variation is two-fold. The 
leaves are bordered, and are also much narrower 
than in the type. 

Gillyflower, called Savoyarde, with variegated 
leaves. 

This is a sport from the double-flowered brown 
gillyflower. 

GrajDe. See Vine, 

Hedera. Variegated tree-ivy. 

This sub- variety is a bud- variety from the so- 
called tree-ivy (lierre en arhre^) from which it 
varies only in the yellowish-white variegations of 
the leaves. 

What we call tree-ivy is a common ivy, or one 
of its varieties, arrived at the full-grown state and 
which then fruits. The branches are large, short, 
cylindrical, and destitute of climbing roots. The 
leaves, instead of being lobed, are heart-shaped, 
more or less lengthened, sometimes very obtusely 
rounded. As there are several forms of creeping 
ivy, so there are several sub-varieties of the tree- 



190 BORROWED OPINIONS. 

ivy. They partake of the character of the varieties 
from which they come and are distinguished by the 
form and dimensions of the leaves, by the size of 
the branches, these characters all depending upon 
the vigor and appearance of the mother varieties. 
We obtain the tree-ivy either by cuttings or by 
grafting from adult branches, that is, branches 
which have been modified by fructification. They 
then branch and form very pretty bushes. Some- 
times, especially near the ground or in badly aired 
places, branches arise supplied with climbing roots, 
bearing leaves more or less lobed, and which creep 
and take root as soon as they touch the ground. 
Here, in the case of the tree-ivy, is an instance of 
bud-variation due to the maturity of the individual. 

Hibiscus Syriacus, flore pleno variegata. 

This variety, whose leaves are variegated with 
yellowish- white, ajDpeared in 1858 upon a plant 
with entirely green leaves. 

Hibiscus Syriacus, variegata. 

Remarkable in the variegation of its leaves. Its 
flowers are similar to those of the last. It is a va- 
riation directly from the type. It is not vigorous. 

Hyacinth. 

The double blue or Globe terrestre is a bud- 
variety from the double white or Sultan Achmet. 



carriere's list of bud-varieties. 191 

The double white with blue eye, or Sphsera Muudi, 
is a sport from the double white. The single red, 
called Acteur, cultivated for a very long time 
without varying, has produced by bud-variation 
at Hemstede, near Haarlem, a variety with double, 
imbricated red flowers. The hyacinth Ami du 
Cceur, with single blue flowers, also long culti- 
vated without varying, has produced, from the 
same bulb, two flower stalks, one of Avhich bore 
flowers dregs-of-wine color, while the other bore 
flowers of a delicate flesh-colored rose. 

Hydrangea Hortensia. 

This sterile plant is a sport from the form called 
H. Japonica, analogous to those which are pro- 
duced upon Viburnum Keteleerii and V. Opulus. 

Hydrangea Japonica, variegata. 

Differs from the type only by its leaves being 
bordered with white. 

Ilex Aquifolium, calamistrata variegata. 

This variety is a sport from the T. calamis- 
trata, which is a sport from the common holly. 

Ilex Aquifolium, ferox aurea, and ferox argentea. 

Bud-varieties from the variety ferox, from 
which they differ in the variegation of the leaves, 
yellow in the first, white in the second. 



192 BORROWED OPINIONS. 

The very numerous varieties of common holly 
in cultivation are for the most part fixed bud- 
varieties. 

Iris spectabilis. 

This plant, so remarkable for its color, is a bud- 
variety from Iris Xiphium, from which, however, 
it is very different. 

Juniperus communis, variegata. 

Juniperus excelsa, variegata. 

Juniperus Virginiana, variegata. 

Juniperus Virginiana, monstrosa. 

This variety, which arises from knaurs or burrs, 
is shown frequently upon the Virginian juniper 
(red cedar). 

Lamium album, variegatum. 

Laurocerasus vulgaris, angustifolia. 

This plant, Avhich for a long time has gone under 
the name of Hartogia Capensis, is a bud- variety, a 
fact which we liave been able to ascertain several 
times. Its leaves are very straight, long, of a 
clear green, and more strongly toothed than those 
of the plant from ivhich it comes. It is very con- 
stant. We have a record of its variation. 



caeriere's list of bud-yarieties. 193 

Laurocerasus vulgaris, variegata. 

Lanrocerasus Lusitanica, variegata. 

Ligustrum Japonicum, variegatum. 

The L. Japonicum appears to be subject to bud- 
variations, especially in the direction of dichroism. 
We have already produced from it several varie- 
ties distinct in the color or disposition of the 
variegations, the varieties receiving names accord- 
ing to their character. There is one which differs 
somewhat in the form of its leaves. 

Ligustrum ovalifolium, aureum. 

This variety, which is distinguished by having 
its leaves bordered or ribboned with yellow, was 
produced at the Museum in 1861. It comes from 
a branch which was developed spontaneously upon 
a type plant. It is unstable. 

Ligustrum vulgar e, variegatum. 

This variety has leaves variegated with yellow. 
It occurs quite frequently in the wild state. We 
have found it several times in the woods. It is 
not stable. 

Lilac, common, variegated. 

Lilac, Persian, laciniate-leaved and white-flowered. 

Although we are not able to state precisely when 
these two sports appeared, we have no doubt that 



194 BORROWED OPINIONS. 

they are bucl-varieties, as the Persian lilac never 
gives seeds. The origin of the Persian lilac itself, 
even, is in much doubt. 

Mamillaria nivea, dedalea. 

This variety forms a compact mass whose folds 
and circumvolutions are disposed in a sort of laby- 
rinth (whence dedalea)^ giving it a little the ap- 
pearance of calves' pluck. The type from which 
this variety comes forms a melon-formed cylinder 
which is slightly swollen at the summit. It bears 
spines disposed in bundles and from about four- 
fifths inch to one inch and a fifth in length, rigid, 
very sharp, surrounded at the base by a series of 
smaller ones disposed in the form of a star. The 
variety, on the other hand, aside from its peculiar 
form, has no spines. It is invested upon all its 
parts with silky hairs, silvery and as soft as felt 
to the touch. The parent and offspring have 
nothing in common in their general form. 

Mentha rotundifolia, variegata. 

Molinia coerulea. variegata. 

Musa paradisiaca, vittata. 

This is distinguished from the type by the white 
bands upon its leaves. The variegation is con- 
spicuous upon the yellow plants. It often disap- 
pears with time, so that in the old plants we do 
not often find any trace of it. 



cakriere's list of bud-vaeieties. 195 

Myrtle, common, variegated-leaved. 
Frequently returns to the type. 

Opuntia oylindrica, cristata. 

In exterior characters this plant has nothing in 
common with the type, which forms a regular, 
cylindrical column. The variety, on the contrary, 
is made up of enlarged pieces placed against each 
other in different ways, much the same as those 
presented by the various species of opuntia which 
we call ''Semelles du Pape." 

Orange tree, Turkish. 

This variety, which is a sport from a kind of 
Seville orange (probably from the Horned Seville 
orange), bears at times upon its various branches 
leaves narrow and irregular (as erose), variegated 
or rather satin-bordered, white, and, upon other 
branches, green leaves, large and strongly eared, 
as well as fruits which recall those of the Horned 
Seville orange. 

Orontium Japonicum, variegatum. 

Osmanthus Fortunei,^ ovata. 

This variety is unstable. After having pre- 
served it for more than a year without varying, it 
has resumed in large part its primitive character, 
which is to have leaves long, exceedingly thorny 

1 The Olea ilicifolia of commerce. — Carriere. 



196 BORROWED OPINIONS. 

and strongly nerved. Sometimes we find branches 
bearing leaves of different forms. 

Osmantlius Aquifolius, variegatus. 

Differs from tlie type by the yellowish- white 
variegations of the leaves. 

O. Aquifolins, which we can consider as the 
representative in Japan of our common holly, 
appears, like the holly, to be very subject to bud- 
variation. We have no doubt that the varieties 
recently introduced from Japan originated in this 
manner. 

Peach, carnation-flowered (Persica dianthiflora), 
and many-colored (P. versicolor). 

These two varieties are sportive forms of P. 
rosseflora, of which the flowers are very deep 
red. Like this, the two varieties have double 
flowers, but of very different colors from those of 
their parent. The carnation-flowered has flowers 
of a flesh-colored rose. The many-colored, on 
the contrary, has white flowers striped or rib- 
boned with brilliant rose. This last is very much 
more delicate than P. rosasflora or the carnation- 
flowered. 

Peach, willow-leaved red Madeleine. 

This variety, remarkable for the form of its 
leaves, which are very long and narrow, plane. 



caeriere's list of bud- varieties. 197 

glossy, very shortly toothed, is the result of a 
bud-variation from the variety designated by cer- 
tain horticulturists as Madeleine de Courson (red 
Madeleine). It appears to us to have great re- 
semblance to that very anciently known as the 
willow-leaved. 

Peach, laciniate-leaved red Madeleine. 

Leaves very strongly and coarsely toothed or 
laciniated. 

Pears, variegated fruited. 

The following pears have given b}^ bud-varia- 
tion variegated varieties : Duchesse d'Angouleme, 
Amanlis, Guenette or Madeleine, Saint-Germain, 
Bergamotte d'automne, Culotte de Suisse, etc. 
These bud- varieties are further remarkable in that 
the v^ariegations extend to the branches and fruit, 
but not to the leaves, a character which distin- 
guishes them from the next variety, which is like- 
wise a bud-variety. 

Pear, Amanlis, with yellow bark and leaves. 

A very remarkable variety. We could almost 
say that it is pretty. It was developed upon a stem 
of Amanlis which presented nothing abnormal. 
It is very vigorous, and produces a most singular 
effect, with its parts all yellow except the bark, 
which is grayish-white. It has not yet fruited. 



198 BORROWED OPINIONS. 

[One of the most marked cases of bud- variation 
which ever came under my notice was observed 
a few years ago upon a tree of Onondaga pear. 
One branch, so placed as to remove all possibility 
of its being a root-sprout or a graft, bore about a 
dozen pears which were intensely and uniformly 
russeted. They were so different in appearance 
from the pears upon the remainder of the tree that 
no one would suppose for a moment that they were 
the same variety. Even the Sheldon does not 
differ more widely from the Onondaga in appear- 
ance than did this singular sport.] 

See page 174 for further notes on the pear. 

Pelargonium zonale, Manglesii. 

Distinguished from the species by its white 
variegated leaves, which are more deeply lobed, 
and by the weaker branches. It has, in its turn, 
produced several varieties by bud- variation. 

The bud-varieties produced by P. zonale and P. 
inquinans (which are in reality only one) are very 
numerous. There are among them some varieties 
of such pronounced characters that, if we ignored 
their origin, we might consider them species. 

Pelargonium hedersefolium, variegatum. 

Phalaris arundinacea, picta and aurea. 

These two varieties differ from the species in 
the variegation, which is produced by white in 



cakriere's list of bud-varieties. 199 

the first case and yellow in the second. They 
are exactly representative of the phenomenon 
which is observed in Arundo Donax, as well as 
in the sngar-cane. 

Phlox decussata, white Croix de Saint-Louis. 

This variety, of which the flowers are entirely 
white, appeared upon the variety Croix de Saint- 
Louis in 1863. The parent variety lias white- 
striped rose flowers, and cross-form, whence its 
name. 

Phragmites vulgaris, variegata. 

Leaves bordered or margined with white. 

Picea excelsa, tabulseformis. 

This variety, which attains a height of scarcely 
more than a foot or two, and which spreads out 
horizontally so as to form a sort of carpet, is a 
most remarkable variation which resulted from 
a knaur or burr upon the stem of a very large 
spruce. It was produced in the park of Trianon 
at Versailles. 

Pinus sylvestris, nana monstrosa. 

Produced from a knaur from the stem of a 
large pine. It is dwarf and monstrous, remarka- 
ble for its long, unequal, crowded leaves, and 
by its slender, sometimes almost filiform, irreg- 
ular branches, which are produced in such quan- 



200 BORROWED OPINIONS. 

tity that they sometimes completely conceal the 
branches and even the trunk. 

Pinus sylvestris, nana compact a. 

This variety is also the result of a knaur from 
a large pine. It attains but a foot or two in 
height. Its very short and numerous branches 
have already borne two crops of cones, some 
nearly ripe, small, though well formed, others 
much younger, still herbaceous. 

Pittosporum Tobira, variegatum. 

Populus Grseca,^ pendula. 

We cannot say whence this variety came nor 
how it was obtained. It has been in cultivation 
very long. We have a singular experience to 
record concerning it. In 1858 we grafted fifteen 
plants of P. nivea with P. Grseca, and, seven of 
the grafts growing, there was one which produced 
slender and drooping branches just like the variety 
pendula of P. Grteca, of commerce. This phe- 
nomenon is one of the most curious which we 
know. The tree is planted in the nursery of the 
Museum at the side of one of its brothers, to 
which, physically, it bears almost no resemblance, 
although coming from the same parent plant. 

1 Undoubtedly our native large-toothed aspen, Populus 
grandidentata. — L. H. B. 



careiere's list of bud-varieties. 201 

Both are pistillate and are covered each jesir 
with catkins. 

Potato. 

Potatoes furnish many examples of bud-va- 
riation ['Mnixing in the hill"]. Many of our 
cultivated varieties are bud-varieties from the 
subterranean parts. Every year at digging time, 
if we wish to keep the varieties true, we are 
obliged to throw out those which, we say, are 
"degenerated." This so-called degeneracy con- 
stantly tends to remove the products from the 
starting-point, and has, then, the result of pro- 
ducing new varieties. 

Modifications in potatoes may also occur in 
the manner of vegetation or growth of the under- 
ground parts. Such is the case in the variety 
called Pouse-debout [" tubers standing on end "] . 
This name was given the variety because the 
tubers, instead of lying horizontally, or nearly so, 
are placed upright, one against the other, much as 
small pieces of wood are arranged for the making 
of charcoal. 

The Marjolin we consider nothing else than a 
peculiarity of vegetation. This is proved by the 
fact that its characters — - not blossoming and 
maturing very early — are not constant. It has 
produced two other varieties by modifications of 
its underground parts. One variety is the Mar- 



202 BORROWED OPINIONS. 

jolin tardive [Late Marjolin], called also Marjolin 
de deuxieme Saison, which is sometimes sold in 
the Paris markets for the Hollande jaune [Yellow 
Holland]. It is remarkable for the period of its 
growth, w^hich is more prolonged than that of the 
type, and it is also covered each year with flowers, 
while its parent scarcely ever blossoms. The 
other variety has no resemblance to the ]Mar jolin 
in form. It is ronnd, and its snnken eyes give 
it exactly the apj^earance of the ordinary yellow 
potato. When we cultivated the Marjolin there 
was not a year when we did not obtain round 
ones, although we had planted long ones very true 
in appearance. 

A very remarkable example of the modifications 
furnished by the ordinary yellow potato is the 
following : In a square planted exclusively with 
this variety, very true in appearance, we gathered 
a certain number of which the skin Avas more or 
less dark ; some had yellow flesh, others white. 
Planted separately, these bud-varieties have given 
us potatoes round in form like the parent type, 
but among which there were found some entirely 
violet in both exterior and interior, and some had 
black flesh slightly marbled with white. This 
modification of color was not the only change. 
In some cases the quality was very much modified. 
Thus, instead of being nearly like the yellow 
potato, the flesh of these varieties was compact, 
neither good nor bad. 



cahriere's list of bud-varieties. 203 

We give two other examples of bud-variation 
in potatoes, observed by us at the Museum in 
1864 : Half of a plat was planted with the smooth 
long yellow called Hollande, and half with the 
regular long red commonly called Vitelotte lisse. 
The first half yielded tubers similar to those 
which we had planted. The second half, on the 
contrary, produced tubers differing from the pa- 
rent in color, being of a reddish-yellow, although 
the form remained about the same. The quality, 
also, did not vary, so that while we confounded 
them sometimes with the Hollande, we were able 
to distinguish them readily when cooked, as 
they remained whole, while the others fell to 
pieces. 

On the end of a plat where we had planted fifty 
of the ordinary round yellow potato, one plant 
grew until late in the season and gave round 
potatoes of a deep red. 

In this same year, 1864, in a square planted 
entirely to Chardon potato, we observed some 
plants exactly similar to the others in groAvth and 
appearance, but which differed entirely in the 
color of the flowers, being dull white, a little 
sulphur-colored, while those of Chardon are violet- 
rose or rose-violet. The tubers from these Avhite- 
flowered plants differed from those of the type in 
being more round and regular and having less 
pronounced eyes. Aside from these variations, 



204 BORROWED OPINIONS. 

we have found among the Charclon both earlier 
and later varieties, and this in spite of the fact 
that we had planted only such tubers as appeared 
to be entirely true and which for a long time had 
produced no variations whatever. Here, as in 
the preceding cases, the modifications were from 
the tubers, seed not having been sown. 

An instance similar to the above is reported by 
M. Joigneaux in the Journal de la Ferme et des 
Maisons de Campagiie : Nine or ten years ago six 
beautiful tuljers of a long, pale j^ellow potato were 
given us. In order to increase the number of 
hills we divided each tuber into three pieces. We 
planted them ourselves. The cultivating was also 
done by us. Some of the potatoes, a very small 
number, resembled the type, but the larger num- 
ber were spherical, some yellow like the j^arent, 
others deep red. . 

All cultivators know that the smooth or even 
Vitelottes, whose eyes are few in number and 
scarcely perceptible, often produce tubers of vari- 
ous forms and with eyes so much sunken that it 
is almost impossible to peel them. Once ive ob- 
tained a variety which, besides the many and deep 
eyes, produced, in considerable quantity, agglom- 
erations which gave to the Avhole a monstrous 
form. They were veritable hydras. Although 
coming from the Vitelotte, which is a good potato, 
this variety was very acrid and bad. 



caeeiere's list of bud-yaeieties. 205 

All these examples sliow without doubt how 
a part of the varieties of potatoes are pro- 
duced, and proves that they do not all come 
from seeds. We may convince ourselves of it 
when, having observed the growth of the j^lants, 
we mark the peculiar plants and gather their 
tubers separately. See, also, page 209. 

The phenomena presented by potatoes prove 
that the cause of the appearing of new varieties 
is not always due, as we generally suppose, to 
crossing, as fecundation can act only upon the 
seeds. It is also very rarely that we practise 
crossing in potatoes, but we can number the varie- 
ties by the hundred. But it often happens that 
cuttings made from portions of the top of the plant 
produce varieties different from the parent. More- 
over, the existence of numerous varieties of certain 
plants which we cultivate and which never pro- 
duce seeds, proves beyond a doubt that there are 
causes aside from crossing which tend to the pro- 
duction of new varieties. 

Prunus Mahaleb, varieo-ata. 

Aside from this variety, which is very pretty 
with its long and very slender branches and 
white-variegated leaves, P. Mahaleb has by bud- 
variation given several sub-varieties which are 
distinguished by the form of the leaves, and 
especially by the color of their variegations. 



206 BORROWED OPINIONS. 

Almost all these varieties are more delicate than 
the type. 

Rheum australe, variegatum. 

Remarkable for the beautiful white variegation 
of the leaves. 

Ribes nigrum, variegatum. 

Leaves variegated with yellowish-white. 

Ribes rubrum, variegatum. 

Robinia hispida, arborea and macrophylla. 

R. hispida, var. arborea of the gardens (R. 
macrophylla DC), differs from the type by its 
greater vigor, its branches very much larger, 
the bark dark, glossy, and smooth, and by the 
thicker coriaceous leaves, which are glossy as if 
varnished. R. hispida, var. macrophylla of the 
gardens, is nearer the type than the last; it differs 
from it, however, by its greater vigor, and espe- 
cially in its flowers, which, less abundant and a 
little more developed, are paler in color. Like 
the type, of which even the origin is doubtful, 
these varieties do not produce seeds. 

The fact of the sportive production of the 
variety inermis upon R. hispida is wholly be- 
yond doubt. Several times we have found the 
two sorts of twigs growing side by side upon the 
same branch. It is only necessary to multiply 



cakeieee's list of bud-varieties. 207 

them separately in order to obtain distinct varie- 
ties.^ 

Robinia Pseudacacia, umbraculifera. 

This plant, now so commonly used either for 
ornament, under the common name of Acacia 
boule, or as a dwarf shrub and considered as a 
forage plant, and called in consequence Acacia a 
faucher, comes, according to Turpin, from a knaur 
which appeared on the stem of a R. Pseudacacia. 
This fact does not surprise us. It shows us how 
important these singular excrescences may become. 

Rose Eglanteria, punicea. 

This differs from the ordinary yellow-flowered 
capucine rose (R. Eglanteria) in the color of the 
flowers, which is an orange-red. In many soils 
this variety returns more or less quickly to the 
type. It frequently happens that we may see 
even upon the same stem a red and a yellow 
flower. Sometimes we find a flower which pre- 
sents these colors separately on opposite sides and 
of nearly equal extent, or some petals may be half 
red and half yellow. In general, the sport is less 
vigorous than the type, so that under the influ- 

1 Plants of normally thorny species are often found which 
bear no thorns. There is a so-called variety inermis of the 
honey-locust, Gleditschia triacanthos. Wild blackberries with 
smooth canes are occasionally found. In fact, most prickly or 
thorn-bearing plants vary much in these characters. — L. H. B. 



208 BORROWED OPINIONS. 

ence of a slow modification we sometimes see the 
color gradually disappear, and at tlie end of a 
certain time we have a rose Avith completely yel- 
low flowers in the place where we planted one 
with orange-red flowers. 

For further notes on the rose, see pages 161 to 
170. 

Salix Babylonica, annularis. 

Very remarkable for the form of its leaves. 
For a long time we have noticed it showing itself 
each year upon an old tree. The parts upon 
which it appeared, being generally weak, j)i'0- 
duced, instead of long, linear, plane leaves, those 
which were rolled up on the edges and distorted 
into rings. It is very constant. We have no 
examples of its reverting. It is much less vigor- 
ous than the type. 

Sambucus nigra, variegata aurea and variegata 
argentea. 

These two varieties differ from the species in 
the variegation, which is made by yellow in the 
first, white in the second. The second is much 
less vigorous than the type. 

Sambucus nigra, monstrosa. 

Analogous to Euonymus Japonica, fasciata. The 
flowers are also monstrous, and, up to this time, 
the seeds which they have produced have always 
been poor. 



carriere's list of bud-varieties. 209 

Solanum Dulcamara, variegatum. 

Solanuni tuberosum, variegatum. 

Remarkable for its yellow-variegatecl stems and 
leaves. During the year previous to the appear- 
ing of this variety, its parent type presented no 
unusual characters. See Potato, page 201. 

Spiraea Ulmaria, variegata. 

Symphoricarpus vulgaris, variegata. 

Symphytum officinale, variegatum. 

Thuyopsis dolibrata, variegata. 

This variety, of which the leaves are variegated 
with white, is remarkable for its vigor and its 
facility for forming heads when multiplied by 
cuttings. 

Ulmus campestris, variegata, argentea, aurea picta, 

etc. 

Variegated varieties of the common elm are 
numerous. They are distinguished both by the 
color and form of the variegations. 

Viburnum Opulus, sterilis or Boule de neige. 

Viburnum Opulus, sterilis variegatum. 

Viburnum Keteleerii, macrocephalum. 

Analogous to the sterile varieties of V. Opulus. 



210 BORROWED OPINIONS. 

Viburnum Tinus, variegatum. 

Viola Rothomagensis, pallida. 

This variety, of which the two superior petals 
are pale lilac and spotted, Avhile the three others 
are yellowish-white and lightly striped, was pro- 
duced by bud-variation at the Museum. 

We have said elsewhere that the phenomena of 
bud-variation could be divided into two classes, 
one group including those variations which appear 
abruptly, the other those which take place slowly. 
This violet falls under the latter group. In 
1863 we received from the hills of Vernon a 
certain number of plants of V. Rothomagensis. 
Planted at the Museum, they preserved nearly all 
their characters except the villosity, which in large 
part disappeared the first year. During this year 
1863 and the entire year 1861, they produced blue 
flowers abundantly. In the winter of 1864-65 all 
the plants perished except one. The remaining 
plant, instead of being covered with beautiful 
blue flowers as it had been the two preceding 
years, produced flowers almost white. ^ 

Vine (Grape). 

Bud-variation is comparatively common in the 
vine. [Frequent cases occur in the American 

1 This variation appears, after all, to have been an abrupt 
one. —I,. H. B. 



CAllKIEKE ON GRAPE SPOKTS. 211 

grapes.] It is well understood in this case, as 
the vine is one of the oldest of cultivated plants 
and it is multiplied almost always by cuttings; 
and as cuttings are made by millions each year 
a bud-variety soon becomes widely disseminated. 
It frequently happens that a shoot will produce 
grapes differing in form or color from those which 
are borne upon other shoots of the same vine. We 
may add that these variations nearly always pre- 
sent peculiar qualities also. We will cite ex- 
amples. 

Upon a plant of black-fruited Muscat grape we 
have observed for several years that some shoots 
produce white grapes. 

The white seedless Corinth is a bud-variety 
from a variety which has much larger fruits, with 
seeds. This is a fact which we have several times 
observed upon bunches where some fruits were 
unusually developed and Avhicli contained seeds. 
The white Cornith is analogous to the Chasselas 
de Demoiselles. 

A proprietor of large vineyards in the middle 
of France, the late Cazalis AUut, wrote some years 
ago as follows : — 

"A stock of Teret produced with me, for sev- 
eral years, black grapes upon shoots of two of 
its arms, and gray grapes upon shoots of the other 
arms. A stock of Epiran gris, trained in cordon, 
is now about forty feet long. The first twenty 



212 BORROWED OPINIONS. 

feet produces constantly gray grapes and the re- 
mainder produces white ones. I have in an 
enclosure a stock of Epiran noir having several 
arms. The shoots of one of the arms give grapes 
almost twice as large as those on other parts of 
the vine." 

Another viticulturist, M. Henri Bouschet of 
Montpellier, wrote very recently: — 

" I had occasion for several years to see in my 
collection at Lot-et-Garonne, a plant of Prunella 
gris, which, sometimes upon one stem, sometimes 
upon two, bore black grapes, while the remainder 
of the vine bore gray ones. I have noticed for 
two years in my collection at Calmelte a most 
curious fact upon three grafts of a Spanish va- 
riety which came to me from the collection of 
Luxembourg, where it is called Parrel del Reyno 
de Lorca and which I have recognized as our 
Morastel noir. One of these three stocks has 
borne on one side, to my great surprise, black 
grapes similar to those of the Morastel, and upon 
the other side, constantly, white bunches having 
an appearance very different from an ordinary 
white Morastel, and presenting a foliage very 
different in size and form. This odd foliage ap- 
pears to me to be identical with that of the Oyo 
de Rey de Morada, of which the bright yellow- 
ish-green leaves present very shallow rounded 
dentate lobes, while the leaves of the Morastel are 



CAEEIERE ON GRAPE SPORTS. 218 

deep green with deep divisions, the lobes acute, 
with teeth detached and terminating in a point." 

A passage which we find in the Parfait 
Vigneron (edition of 1811) seems to confirm the 
opinions which we give concerning bud-variations 
in grapes : — 

'' A citizen of Vilmorin has observed a stock of 
jNleunier to bear, upon some shoots, leaves and 
fruits of Maurillon precoce. A citizen of Ju- 
milhac has seen likewise the Meunier become 
Maurillon." 

Therefore the grape called Madeleine Juillet, 
Maurillon hatif, etc., is only a sport from Meunier, 
a fact which shows, as we have said before, that 
the varieties produced by bud-variation may pre- 
sent qualities different from those presented by 
the plants from which they come. 

Upon a plant of Pinot gris there appeared at 
the Museum in 1863 a shoot whose leaves Avere 
much variegated or striped with yellow. It 
produced a grape very similar to the variety from 
which it came. It appeared to be much less fer- 
tile, however. 

In 1863 we observed two other very remarkable 
examples. One example concerns the Precoce 
Malingre, the other the variety designated by 
the name of Yerjus. These examples present 
contrary results. Thus, while Precoce Malingre 
has long, oval, scattered fruits, and the bud-variety 



214 BORROWED OPINIONS. 

which a]3peared upon it had round fruits borne 
close together and larger than those of the type, 
the Verjus has slightly oblong or nearly spherical 
fruits and the bud-variety which was developed 
upon it had fruits long-oval and attenuated at 
both ends, and somewhat later than those of the 
type. 

The Chasselas gros Coulard is a bud-variety 
which appears frequently upon the ordinary 
Chasselas. Its fruits are large and spherical. 
They often drop. It differs especially from the 
Chasselas by its stronger shoots with joints 
much closer together, and by its leaves being 
less lobed, a little longer and thicker, of a 
glossy green as if varnished. It differs also 
from the ordinary Chasselas in its temperament. 
It needs much heat and also shelter from the 
influence of the air. It generally succeeds well 
in forced culture. 

The Chasselas de Demoiselles, remarkable for 
its fruits, which are scarcely larger than shot, is a 
bad- variety from the ordinary Chasselas. This 
phenomenon appears to be due to the partial abor- 
tion of the sexual organs and particularly of the 
anthers, whence results the lack of impregnation 
of the flowers and the consequent abortion of seeds. 
Propagated by cuttings, it preserves its characters. 
A variety vfith variegated leaves has appeared 
from the ordinary Chasselas. 



FOCKE OK THE PEIMARY CROSS. 215 

Wigandia Caracassana, variegata. 

Distinct by its leaves and even its brandies 
being variegated witli white. The variety ap- 
peared in 1862 upon a phmt which, placed in the 
open air at the beginning of the season, j)resented 
no unusual characters. 

III. Focke's Discussion of the Character- 
istics OF Crosses. (Translation of Chapter 
IV. of Die Pflaiizen-Mischlinge.^^ 

There is no absolute distinction between plants 
of a pure and those of a. hybrid or mixed descent; 
there are therefore no signs by which one can, 
under all circumstances and wdth certainty, rec- 
ognize the mongrel nature of a certain plant. 
Hybrids, nevertheless, often show a series of 
characteristics which indicate with greater or 
less accuracy their mixed descent. Certain rules 
can be made in regard to them, of which none, 
of course, is without exce^^tion. 

I. the simple primahy cross (A X B) .2 

1. All individuals formed hy the crossing of 
two pure species or races are^ if they have been 

iFocke uses the word mischling (derived from mischen, " to 
mix") in about the same sense in which we use the noun cross ; 
i.e. it is a generic term for both cross-breeds and hybrids. 

2 In these formulas, the letters are used to designate the 
parents of any cross. In common with usage amongst botanists, 



216 BOFvKOAYED OPINIONS. 

produced and groivn under the same conditions^ 
exactly like each other, as a rule, or they differ 
hardly more than specimens of one and the same 
species are ap)t to do. 

This carefully stated proposition, founded upon 
experience, appears to be sufficiently justified by 
numerous experiments, but it is, nevertheless, 
subject to many exceptions. Some students of 
crosses have so limited its application that they 
dared only to assert the similarity of the speci- 
mens obtained from a capsule fertilized by the 
same plant. At all events, the rule proves itself 
to a certain degree trustworthy only in those 
cases in which the similarity of origin and con- 
dition of growth demanded by the terms of the 
rule are really present. 

The question easiest to answer is just the one 
about which there has been the most violent dis- 
cussion, namely, that relating to the stronger 
influence of the one or the other sex upon the 
offspring. The crosses of the two species or races 
A and B resemble each other whether A was male 
or female in the crossing. Experimenters, es- 
pecially Kolreuter, Gartner, Naudin, and Wichura, 
have not, on the whole, been able to find any 

arbitrary signs are used in the text to designate the sex of each 
parent. The sign ^ represents the male, or the parent which 
furnished the pollen ; 9 stands for the female or seed-bearing 
parent. — L. H. B. 



FOCKE ON THE PRIMARY CROSS. 211 

difference between A 9 x B <? , and B $ x A ^ . 
More than one hundred years had passed since 
Kolreuter had proved the conformity of Nicotiana 
rustica 9 x paniculata ^ , and N. paniculata 9 X 
rustica S' , Avhen one of the acutest florists of our 
time, Timbal-Lagrave, was also astonished in the 
highest degree by a similar experience. All the 
rules and supposed experiences according to Avhich 
the florists were to know, from the morphological 
characteristics of a hybrid, which of the progeni- 
tors had furnished the pollen for its formation, 
and which had borne the seed, are entirely ground- 
less and foolish. Besides, it has been 23roved by 
many experiments, that in the vegetable kingdom, 
with regard to species, as a rule, the form-deter- 
mining power of the male and female elements in 
the progeny is entirely equal. 

As with all other rules touching the crossing of 
plants, this one of the similarity of the products 
of reciprocal crossings is not without its excep- 
tions. It is a matter of course that an observed 
difference can be ascribed, Avith any probability, 
only to a stronger influence of the male or female 
elements, provided that the experiments are car- 
ried on in exactly the same manner, and if they 
always lead to the same result after repeated 
trials. So far, almost all the recorded experi- 
ments could be improved in this respect, for they 
are open to justifiable doubt. The following 



218 BORROWED OPINIONS. 

declarations of the differences in the products of 
reciprocal crossing seem worthy of notice. 

a. The influence of the female element in Pe- 
largonium fulgidum X grandiflorum, P. peltatum 
X zonale, Epilobium hirsutum x Tournefortii,^ ex- 
ceeds that of the male as regards general form. 
This influence is also shown more strongly in the 
colors of the flowers of several hybrids of Dig- 
italis, in some also in the form of the corolla. In 
Nymphtea rubra x dentata, the seed-leaves resemble 
those of the female progenitors. 

h. The female element shows, apparently, an 
overpowering influence in the power of with- 
standing cold in the Rhododendron (hybrids of 
R. arboreum), Lycium, and perhaps also in Cri- 
num (hybrids of C. Capense). 

c. The male element influences the general 
form especially in Papaver Caucasicum x somni- 
ferum, and Cypripedium barbatum x villosum (if 
constant ?) ; it shows a stronger influence upon 
the colors of the flower in Petunia. 

d. Gartner says that he has sometimes observed 
differences in the fruitfulness and progeny of re- 
ciprocal hybrid forms, e.g. in Dianthus barbatus 

X superbus. The experiences of Gartner should, 
however, hardly suffice to establish the uniformity 
of this occurrence. 

The principal differences between A 9 and B $ 

1 The various examples cited in the text are fully explained 
in the body of Focke's work, Die Pflanzen-Misclilinge. 



FOCKE OK THE PRIMARY CROSS. 219 

and B 9 and A ^ , have been observed by Kolreuter 
and Gartner in some Digitalis hybrids. That 
these differences really show themselves each time 
and in the same manner, is by no means proved. 

Much oftener, the departures from the regular 
uniformity of single specimens, observed among 
hybrids, are entirely independent of the influence 
of the species in the hybrid formation. Often 
important differences appear among the seedlings 
of the same cross which have been treated exactly 
alike. These differences show themselves in dif- 
ferent ways : — 

1. Single specimens of the cross may show but 
slight differences among themselves, especially in 
the color of the blossoms and similar character- 
istics, which are easily changed ; compare, for 
example, the hybrids of Verbascum phoeniceum, 
Salix Caprea x daphnoides. 

2. The cross may appear in two different types, 
each of which represents a different combination 
of the characteristics of the progenitors. As a 
rule, one type more closely resembles the one, and 
the second the other progenitor ; the numbers of 
the two types are often very unequal. Gartner 
designated the rarer forms " exceptional types " 
(^Ausnahmetypus). For examples, study Cistus, 
Dianthus, Geum, Oenothera, Lobelia, Verbascum 
Thapsus X nigrum, Nicotiana quadrivalis x Taba- 
cum, var. macrophylla. 



220 BORROWED OPINIONS. 

3. The cross may appear in several different 
types. Gartner gives some examples of these, 
although in his cases it is probably a question of 
three known forms of one polymorphous union. 

4. The cross may appear in a typical interme- 
diate form, and a number of vacillating ones 
approaching one or the other parent, and among 
which no distinct type can be distinguished. 
Such is Medicago falcata x sativa, usually also 
Melandrium album x rubrum. 

5. The cross may have from the beginning 
very many forms. The experiments which have 
been made leave it doubtful if in these cases one 
or more constant types, with a similar combina- 
tion of characteristics, can be distinguished among 
the vacillating forms. Study Abutiion, hybrids 
of Pelargonium glaucum, P. radula x myrrhi- 
folium, Passifiora, Hieracium, Nepenthes, Narcis- 
sus. Gartner made the assertion that hybrid^a 
between two species are of similar form, whilst 
crosses of varieties are polymorphous. If, by va- 
rieties, is understood the unsettled garden forms 
or garden crosses, then the remark is justifiable ; 
but if fixed races of pure descent are also included, 
then it is decidedly wrong. See '' Cross-breeds 
and Hybrids" (section III., page 247). 

Entirely different results are obtained by com- 
paring hybrids which, although springing from 
the same species, were produced and grown in 



FOCKE OiT THE PRIMARY CROSS. 221 

different places. Spontaneous hybrids are, as a 
rule, much more variable than those produced 
artificially, e.g. Yerbascum Lychnitis x Thapsus 
and V. Lychnitis x nigrum. My hybrids between 
Digitalis purpurea and D. lutea resembled each 
other much when I had sown the seeds ; on the 
other hand, very different forms arose when the 
seeds had accidentally sown themselves. It may 
be that in this case there was no real causative 
connection between the many forms and the man- 
ner of sowing ; nevertheless it is certain that 
several growers have very often obtained different 
results in their crossings from the same species. 
The uniformity of all the products of the same 
crossing, which undoubtedly is the rule with the 
experiments of growers, appears in nature rather 
to be the exception than the rule. It remains to 
be ascertained what influence the unequal nour- 
ishment of the parent species, or of the hybrid 
seedlings, has upon the variability of the hybrids. 

2. The characteristics of the crosses maij he differ- 
ent from the characteinstics of the ])arent species. 
It is in size and luxuriance (^see proposition 3), as 
well as in their sexual ability/ (^see p)roposition 4), 
that they differ inostfrom both parent species. 

The manner differs in which the characteristics 
of the parent species are united in the cross. 
Generally, a blending or mutual union takes 
place, but often in such a manner that in one 



222 BOKliOWED OPINIONS. 

respect one, and in another respect the other 
parent seems to appear. Sometimes, for example, 
tlie cross resembles one parent in the leaves, and 
the other parent in the flower. Sometimes there 
appears a variety of the cross, in which the char- 
acteristics are distrihnted in the reverse order. 
Some crosses resemble at first one species, and 
later the other parent species ; as their leaves 
show in the spring the one and in the fall the 
other type (Cistus, Populus); or the colors of 
the flowers change during the blossoming (Melan- 
drium album x rubrum, Epiiobium roseum x 
montanum ; compare also Lantana), or in the fall 
(Nicotiana rustica x Tabacum, Tropoeolum, Lobe- 
lia, jetc), also sometimes in different years (Bletia 
crispa x cinnabarina, Galium cinereum x verum). 
By the union of races (rarely in hybrids in the 
more restricted sense of the term), one finds, 
among other things, the characteristics of the par- 
ent species unmixed beside each other (compare 
Cucumis Melo, the thorniness of the Datura 
fruits, color of the flower in Rhododendron Rho- 
dora X calendulaceum, R. Ponticum x flavum, 
Anagallis, Linaria vulgaris x purpurea, Calceo- 
laria, Mimulus, Mirabilis). The colors of the 
flower often appear in an unexpected and unex- 
plainable manner : the hybrids of Verbascum 
plia?niceum are very variable in the colors of 
the flowers, and in other respects quite uniform; 



FOCKE ON THE PRIMAllY CllOSS. 22S 

on the hybrids of Helianthemum have sometimes 
been found differently colored flowers on the 
same stalk, at the same time. 

From the crossing of closely related races, 
especially varieties in color, there often appear 
plants which exactly or very closely resemble the 
parent types; compare Brassica Rapa, var., Linum, 
Pismn, Phaseolus ; Anagallis, Atropa, Datura 
Stramonium, Salvia Horminum, etc. Usually 
the influence of the second parent race does not 
show itself till the second generation; and, in 
fact, in such a manner that a part of the seed- 
lings return to that form, either entirely or only 
in certain respects. Only in Atropa, no return 
to the (slightly fixed) yellow form has been 
observed. 

In some cases, the cross resembles one of the 
parent forms so much that it could be considered 
as only a slight variation of the same. Even in 
crosses between two considerably different species, 
the predominating influence of one parent species 
is sometimes shown in a striking degree. The 
hybrid of Dianthus Armeria x deltoides resem- 
bles D. deltoides much more than the other 
parent species ; of D. Caryophyllus x Chinensis 
resembles D. Caryophyllus ; of Melandrium ru- 
brum X noctiflorum resembles M. rubrum ; of Ver- 
bascum Blattaria x nigrum resembles V. nigrum ; 
of Digitalis Intea x purpurea resembles D. lutea. 



224 BOEROWED OPINIONS. 

Sometimes even the primary hybrids show 
characteristics which are entirely different from 
either parent species ; especially is this the case, 
amongst other things, in the colors of the flowers. 
The most curious is the regularly blue-flowering 
hybrids of the white Datura ferox with the 
equally white D. l?evis and D. Stramonium, 
var. Bertolonii. There are many examples of 
unexpected coloring of the blossoms of hybrids 
from species of colored flowers, while the crosses 
by no means always show the shades of color 
which would be obtained by a mixture of the 
parental pigments. Noticeable instances are 
shown, e.g.^ by Clematis recta x integrifolia, Aqui- 
legia atropurpurea x Canadensis (and others), 
Nicotiana suaveoiens x glutinosa, Verbascum 
pulverulentum x thapsiforme, hybrids of V. 
phoeniceum. Anemone patens x vernalis. Be- 
gonia Dregei x Sutherlandi (and others). In 
the crosses of races, e.g.^ of Papaver somniferum 
and Datura Stramonium, many characteristics 
appear which belong not to the parent forms, but 
to other races of the same species. Nicotiana 
rustica x paniculata sometimes shows the colors 
of the blossoms of N. Texana, a foreign sub- 
species of N. rustica. Other characteristics 
which the hybrids show in a greater degree than 
the parent forms, are, e.g., the greater stickiness 
of some hybrids of Nicotiana (rustica x paniculata). 



FOCKE ON THE PRUMARY CROSS. 225 

the apparently greater wealth of honey in N, 
rustica x paniculata, the stronger nauseous odor 
of the hybrids of Melandrium viscosum, the 
supposed increase in the quantity of quinine (?) 
in hybrids of Cinchona (according to Kuntze). 

In later generations of hybrid growth, devia- 
tions from the characteristics of the parent species 
are much oftener observed. 

3. Crosses of different races mid species are dis- 
tinguished from plants of a pure race^ as a rule, 
hy the power of vegetation. Hybrids between very 
different species are often very weak., especially 
when young^ so that it is difficult to successfully 
raise the seedliiigs. On the other hand^ crosses of 
more closely related species and races are., as a 
rule., uncommonly luxuria7it and strong ; they are 
distinguished mostly by size., rapidity of growth., 
early flowering., abundance of flowers., longer life., 
stronger reproductive power., unusual size of some 
special organs., and like characteristics. 

For a closer confirmation of this jDroposition, it 
will be to the purpose to refer to some examples. 
Delicate seedlings are mentioned, e.g.., in Nym= 
phsea alba crossed with foreign species, Hibiscus, 
Rhododendron Rhodora with other species, R. 
Sinense with Eurhododendron, Convolvulus, poly- 
phyllous Salix hybrids, Crinum, Narcissus. The 
experience that seedlings of hybrid-fertilized seeds 
are delicate, is frequent. A dwarfish growth has 



226 BORKOWED OPINIONS. 

rarely been observed in hybrids, although there 
are some instances of it. Large growth is, on the 
other hand, much more common, e.g.^ Lycium 
Datura, Isoloma, Mirabilis. Usually the hybrids 
exceed in height both parent species, or at least 
their medium height ; compare, e.g.^ many hybrids 
of Nicotiana, Verbascum, Digitalis. The vege- 
tation sometimes takes place exceedingly fast. 
Klotzsch emphasizes the rapid growth of his 
hybrids of Ulmus, Alnus, Quercus, and Pinus. 
The flowering time often comes earlier than in 
the parent species, e.g.^ in Papaver dubium x 
somniferum, some Dianthus hybrids. Rhododen- 
dron arboreum x Catawbiense, Lycium, Nicotiana 
rustica x paniculata, Digitalis, Wichura's six-fold 
Salix hybrid, Gladiolas, Hippeastrum vittatum x 
Reginte, etc., but especially in many hybrids of 
Verbascum. On the other hand, there are, no 
doubt, also single hybrids which blossom only 
after a long period, or not at all, e.g.^ in the genera 
Cereus and Rhododendron. Only one example 
of earlier maturity of seeds, independent of an 
earlier maturing of the blossoms, is known to me, 
namely, in Nuphar. Very often and very com- 
monly an extraordinary abundance of flowers has 
been observed in hybrids ; compare, e.g.^ Capsella, 
Helianthemum, Tropyeolum, Passiflora, Begonia, 
Rhododendron, Nicotiana (rustica x jDaniculata, 
glutinosa x Tabacum, and others), Verbascum, 



FOCKE ON THE PEIMARY CROSS. 227 

Digitalis, many Gesnerace?e, Mirabilis, Cypripe- 
dium. The size of the blossoms is often increased 
in hybrids; in a cross of two species with different 
sized flowers it is not rare that the flowers of the hy- 
brid attain the size of those of the larger-flowered 
parent, or almost that size. Dianthus arenarius x 
superbus, Rubus c^esius x Bellardii, hybrids of Rosa 
Gallica, Begonia Boliviensis, Isoloma Tydseum, 
give examples of uncommonly large flowers. 

A strong vegetative reproductive power is very 
common among hybrids ; compare, e.^., Nympheea, 
hybrids of Rubus csesius, Nicotiana suaveolens x 
Tabacum, var. latissima, Linaria striata x vulgaris, 
Potamogeton. A longer life is especially notice- 
able in some hybrids of Nicotiana and Digitalis. 
A greater power of resistance against cold is also 
noticeable in Nicotiana suaveolens x Tabacum, var. 
latissima, while Salix viminalis x purpurea is said 
to be more sensitive to frost than either of the 
parent species. 

These facts indicate partly a certain loss of 
vigor which is inherent to the hybrids on account 
of their abnormal descent, and partly, on the con- 
trary, an exceptional vegetative power. This 
latter fact, which occurs much oftener than the 
former, has only lately been elucidated to any 
extent. The important experiments of Knight, 
Lecoq, and others, liad been known for some time, 
but only through the careful researches of Charles 



228 BOEEOWED OPINIONS. 

Darwin has tlie favorable influence of a cross 
between different individuals and races of one 
and the same species been clearly shown. The 
strengthening of the vegetative power in some 
hybrids is evidently a universal experience which 
needs no special explanation, on account of the 
peculiar circumstances of the formation of the 
hybrids. It was formerly thought that the di- 
minished sexual fruitfulness is compensated by a 
greater vegetative luxuriance, a statement the 
untenableness of which, as Gartner showed, is 
most plainly shown by the fact that many of the 
most fruitful crosses (Datura, Mirabilis) are also 
distinguished by an enormous growth. 

4. Hybrids of differe7it species often form in their 
anthers a smaller number of iiormal pollen grains^ 
and in their fruits a smaller 7iumher of normal seeds^ 
than plants of a pure descent; sometimes they pro- 
duce neither pollen nor seeds. In crosses of nearly 
related races., this tveaJcening of the sexual organs 
does not occur as a rule. The blossoms of sterile or 
slightly fruitful hybrids usually remain fresh for 
a long tivne. 

No characteristic of hybrids has received more 
attention than the diminution of the sexual power 
which has been observed in them. Even Kolreuter 
believed that this characteristic permitted the 
drawing of a sharp line between species and vari- 
eties. The same thought has prevailed amongst 



FOCKE ON THE PRIMARY CROSS. 229 

botanists to a great extent since then, and even 
in very recent times Naudin, Decaisne, and Cas- 
pary have defended the ideas of Kolreuter in a 
more or less modified form. Knight, Klotzsch, 
and formerly also Gordon, considered the pollen 
of hybrids to be entirely impotent, a view which 
was even then contradicted by the accurate ex- 
periments of Kolreuter. It has often been wrongly 
declared that Kolreuter had himself spread the 
doctrine of the total sterility of hybrids ; this 
assertion is to be explained only by ignorance or 
by a misunderstanding of the Latin text. Kol- 
reuter, in fact, does not speak of sterility, but of 
lessened fruitfulness, as being a common charac- 
teristic of hybrids. 

The fruitfulness of hybrids is considerably dif- 
ferent, according to the individual genera. For 
instance, the hybrids of Papaver, Viola, Verbas- 
cam, and Digitalis show but little fruitfulness ; 
the hybrids of Anemone, Nicotiana, Mentha, Cri- 
num, the Cucurbitacese, and Passiflora are much 
oftener fruitful, while in Aquilegia, Dianthus, 
Pelargonium, Geum, Epilobium, Fuchsia, Coty- 
ledon, Begonia, Cirsium, Erica, Rhododendron, 
Calceolaria, Qnercus, Salix, Gladiolus, Cypripe- 
dium, Hippeastrum, the Gesneracese, and Orchidse, 
the fruitful hybrids are commoner than the bar- 
ren ones. In the genera Yitis, Prunus, Fragaria, 
and Pyrus, we use the crosses of closely related 



230 BORROWED OPINIONS. 

species as fruit plants ; in Cereus, hybrids of even 
widely different species show undiminished fruit- 
fulness. 

The sterility of hybrids is sometimes shown by 
their exhibiting no inclination to blossom, a char- 
acteristic which has been observed particularly in 
some hybrids of Rhododendron, Epilobium, Ce- 
reus, and Hymenocallis. These are, however, 
rare exceptions, for as a rule hybrids bloom earlier 
and more profusely than the pure species (see 
page 226). 

In hybrids which have flowers of only one sex, 
the staminate blossoms often fall off while they 
are yet buds, as in Cucurbitacea3 and Begonias 
(hybrids of B. Froebeli). Sometimes the anthers 
are arrested in their growth and form hermaphro- 
dite flowers, as has been observed in some hybrids 
of Pelargonium and Digitalis (D. lutea x pur- 
purea form tubiflora Lindl.). The common result 
of the production of hybrids is a different forma- 
tion in the pollen grains in the hybrids from that 
of the parents. Often the anthers of the hybrids 
are dead and contain no pollen, or they are small 
and do not open at all. Such deficiency of pollen 
can be observed, for example, in Rubus Idoeus x 
odoratus, Ribes aureum x sanguineum, Alopecurus 
geniculatus x pratensis. In other cases, the pollen 
dust consists of small powdery grains of irregular 
form and size, which do not swell when moistened, 



FOCKE ON THE PKIMARY CROSS. 231 

and among which are usually found a few well- 
formed pollen cells which are capable of germina- 
tion. Often the number of normal pollen grains 
is greater, and comprises ten or twenty per cent, 
or more, of the whole number. There are often 
found, in a greater or less degree, large angular 
grains capable of swelling, as well as well-formed 
ones, by the side of those dwarfed or stunted. 
Among crosses of closely related species, as Melan- 
drium album x rubrum, there are usually found 
only few irregularities in the form of the pollen 
grains. In a hybrid Sinningia, the pollen of the 
second year of flowering was better than that of 
the first. 

In hybrids of undoubted different species, a 
normal formation of the pollen is seldom seen. 
The statements on this subject require, for the 
most part, corroboration, nevertheless I refer to 
Nymphciea Lotus x rubra. Begonia rubrovenia x 
xanthina, Isoloma Tydseum x sciadocalyx, Salix 
purpurea x repens ; almost perfectly formed pollen 
grains were found in Salix aurita x Caprea, and S. 
viminalis x repens. 

On the other hand, it is still more rare that a 
deficiency of pollen is found in an evident cross 
of races. Perhaps it could be found oftener if 
one sought for it. The only certain example of 
which I know is an Anagallis cross by myself. 
Whether Raphanus sativus and R. Raphanistrum 



232 BORROWED OPINIONS. 

are to be considered as species or races is doubtful. 
Nevertheless there are some crosses of very closely 
related species which appear to be entirely sterile, 
as, for example, Capsella rubella x Bursa-pas- 
toris, Viola alba x scotophylla, Papaver dubium 
X Rhoeas. 

The sexual capabilities of the female organs 
are, as a rule, not so much weakened in hybrids 
as the male. Nevertheless they are greatly 
diminished. Many hybrids never produce fruit. 
Even after many experiments, one must not make 
definite assertions about the absolute sterility of 
a hybrid : in llubus ciesius x Idceus, for example, 
one can see several thousand blossoms remain 
sterile, and nevertheless, now and then, fruit is 
produced. Compare, further. Digitalis lutea x 
purpurea, Lobelia fulgens x syphilitica, Crinum Ca- 
pense x scabrum. A morphologically distinguish- 
able defect of the ovule of hybrids has seldom been 
referred to so far, although it has been observed in 
Cistus, by Bornet. If one Avishes to obtain a defi- 
nite judgment on the female creative power in 
hybrids, he must fertilize the ovules with pollen of 
the parent species, which, as a rule, develops more 
perfect fruit than tiie pollen of hybrids which has 
been weakened in its generative power. In some 
cases, hybrids whose pollen shows but slight 
potency produce normal fruit with pollen from 
the parent, as in Luff a. 



rOCKE ON THE PRIMARY CROSS. 233 

Some liybrids drop tlieir entire blossoms un- 
wilted, with the calyx and flower stalk intact, 
e.g.^ Ribes, Nicotiana rustica x panicnlata, and 
other hybrids of Nicotiana. 

As a rule, the corolla wilts, after a longer 
period, in a normal manner, or is thrown off as 
in the parent species ; but no setting of fruit thus 
takes place, or only a little of very poor character. 
Sometimes the fruit is well formed externally, 
but contains no seed. In many cases hybrids set 
fruit, but to a less extent and with fewer seeds 
than the parent species. Even in crosses of 
closely related species, the number of seeds seems 
to be smaller than in the parent species ; so, for 
example, according to Gartner, in Melandrium 
album X rubrum. Lobelia cardinalis x fulgens, and 
even in undoubted crosses of races of Verbascum. 

Hybrids of essentially different races rarely 
show an undiminished fruitfulness, although no 
noticeable diminution has been proved in Brassica 
Napus X oleracea, Dianthus Chinensis x pluma- 
rius, var. Sibiricus, Pelargonium pinnatum x hir- 
sutum, Abutilon, Medicago, a few Cereuses and 
Begonias, Hieracium aurantiacum x echioides, Ni- 
cotiana alata x Langsdorffii, a few hybrids of 
Erica, Calceolaria, Isoloma, Veronica, and several 
Orchidse. Fruits and seeds in abundance are also 
found in many other garden hybrids, and in many 
wild ones, as in Roses, Epilobiums, Fuchsias, Cir- 



234 BOBROWED OPIKIONS. 

siums, Hieraciums, AVillows, of Lobelia Lowii, 
etc. In these cases, however, one cannot exactly 
ascertain if the plants are primary hybrids, or, 
which is much more probable, if they belong to 
later generations or arose through derivative 
hybridization (^Ruckkreuzungen) . 

In order to set seeds, or at least to produce a 
vigorous progeny, some hybrids require to be fer- 
tilized by other individuals, even though they are 
themselves hybrids ; compare, for example, hybrids 
of Cistus, Begonia, Gladiolus, and Hippeastrum. 
In some hybrids, only the first flowers produce 
seeds, as Aquilegia, Dianthus, Silene, Lavatera 
Thuringiaca x Pseudolbia, Rubus f oliosus x Spren- 
gelii ; in other cases, the first flowers are regu- 
larly sterile, while the later ones are often fruitful, 
as in Datura, Nicotiana rustica x paniculata, N. 
rustica x quadrivalvis, Mirabilis. In longer-lived 
plants, often all the flowers of the first years are 
sterile, while later, when the plant has reached a 
certain age, a few fruits are formed ; this has 
been noticed, for example, in Rubus Idseus x 
ceesius, R. Bellardii x csesius, Calceolaria integri- 
folia X plantaginea, Crinum Capense x scabrum. 

Although, as a rule, the female creative power 
in hybrids is less weakened than the male, 
still there are some cases in which the reverse 
is true ; compare Nymphoea Lotus x rubra, Cico- 
nium X Dibrachya in the genus Pelargonium, 



FOCKE ON THE PRIMARY CROSS. 235 

Lobelia fulgens x syphilitica, Verbascum thapsi- 
forme x nigrum, Narcissus montanus, etc ; these 
are probably, for the most part, only accidental 
occurrences. 

The longer duration of the flowers (especially 
the pollinized ones) on many sterile hybrids, is 
an occurrence which is analogous to the longer 
duration of unfertilized or incompletely fertilized 
flowers. Often in sterile hybrids, especially after 
dusting with the pollen of the parent or a related 
species, the fruits swell more or less without per- 
fect seeds' being formed in them. Externally 
well-formed but seedless fruits are found in Cacti, 
Passifloras, Cucurbits, and Orchids. Gartner has 
studied this characteristic, which is of no special 
use or value in the culture of hj^brids, very care- 
fully ; however, it offers an important proof of 
the truth of the statement that the development of 
the outside coats of the fruits takes place in a 
normal manner on account of the irritation Avhich 
the germinating pollen produces, but that it is 
nevertheless independent of the fertilization of 
the ovule, and the development of the embryo and 
of the seed. 

One can, in general, make the statement that 
hybrids of closely related races are more fruitful 
on the average than those of considerably differ- 
ent species. One can also consider, as a rule, as 
has been shown above, that closely related species 



236 BORROWED OPINIONS. 

form hybrids among themselves more easily than 
those considerably different. Both rides are trne 
only to a certain extent. If one should infer from 
these that hybrids are more fruitful the easier they 
are formed, then he Avould go far wrong. There 
is no definite relation between ease of formation 
and fruitfulness of crosses. 

From a teleological point of view, we formerly 
saw in the sterility of hybrids a means of keeping 
" species " separate. What purpose this separa- 
tion was to serve was not explained, unless it was 
for the convenience of the systematist. Now, on 
the contrary, we ask if the formation and sepa- 
ration of species does not really depend upon 
the fruitfulness of the crosses between the dis- 
tinctly marked races of the parent types. The 
noticeable resemblance between illegitimate and 
hybrid progeny gives us no standpoint for further 
investigation of the cause of unfruitfulness. More 
light may be given by the fact that in the hybrid 
pteridophytes and mosses the formation of sexless 
spores is just as much wanting as is the formation 
of pollen grains in hybrid phanerogams. The 
obstacle to the regular propagation of hybrids 
seems to lie in the development of certain cells 
which have the power to maintain the type of the 
parent form, it being immaterial if these cells have 
sexual functions or not. In any case, more facts 
must be gathered to justify the adoption or pres- 



FOCKE ON THE PROGENY OF CROSSES. 237 

entation of a principle of such scope. This view 
of the situation can even now be considered as a 
hypothesis which certainly as yet offers no expla- 
nation of the limitations of species, but it leads 
the way to a final solution, because it brings a 
long list of different but plainly analogous 23he- 
nomena as facts in the animal and vegetable king- 
doms under one common point of view. 

5. 3IaIfor77iations and curious forms are mucli 
more common^ especially in the floiver parts of 
hyhrids^ than in individuals of a pure descent. 

Compare Papaver, Dianthus, Pelargonium, Ni- 
cotiana. Digitalis. Double flowers ajDpear to be 
formed especially easily in hybrids. 

II. THE PROGENY OF CROSSES. 

Hybrids are more easily and completely fertil- 
ized by the pollen of the parent forms than by 
their own. Exceptions to tliis rule are hardly 
known (although compare Hieracium echioides x 
aurantiacum), although no large number of ex- 
periments have been made in this direction. By 
their own pollen is to be understood the pol- 
len of hybrids of the same cross, as well as that 
of the same individual. When hybrids grow in 
the vicinity of parent forms, they must naturally 
often be fertilized by them. In the progeny there 
will be, therefore, a number of forms between the 



238 BORROWED OPINIONS. 

primary hybrids and the parent species. In sow- 
ing the seeds of hybrids, one cannot always deter- 
mine if fertilization from the parent species conld 
have taken place or not. The general statement 
that the progeny of a hybrid has shown itself to 
be very variable is therefore of little weight or 
worth. Sometimes a hybrid is more easily fertil- 
ized by a third species than by its own pollen. 
Compare, for example, Nicotiana rustica x panicu- 
lata, and Linaria purpurea x genisteefolia. 



1. Progeny of Crosses with their oivn Pollen. 

(Ax B) ^ x{Ax B) $. 

a. If one protects the fruitful hybrids from the 
influence of the parent forms or other related spe- 
cies, then he obtains hybrids of the second genera- 
tion. It seems to me that the progeny of hybrids 
appears or acts very differently according to the 
lengtli of their life. In long-lived plants, the 
mingling and mutual blending of the two types 
which have been joined in the hybrid often ap- 
pears to be more complete, so that the progeny also 
inherits the characteristic of the new intermediate 
form or type in an equal or uniform manner. 

The progenies of one- or two-year hybrids are, 
as a rule, very different and varied in form ; 
compare Pisum, Phaseolus, Lactuca, Tragopogon, 



FOCKE ON THE PKOGENY OF CROSSES. 239 

Datura, Nicotiana alata x Langsdorffii, etc. Ex- 
ceptions are found in Brassica, Oenothera, Nico- 
tiana rustica x paniculata, Verbascum Austriacum 
X nigrum. 

The progenies of hybrids of several generations 
(meli7'jdliriger^ are generally similar, although the 
cases in which the intermediate type shows itself 
to be constant appear to be much more frequent. 
Some hybrids of Aquilegia, Dianthus, Lavatera, 
Geum, Cereus, Begonia, Cirsium, Hieracium, Pri- 
mula, Linaria, Veronica, Lamium, and Hippeastrum 
appear to come very true to seed. 

The progenies of shrubs and trees are, in the 
majority of cases, very constant or invariable ; 
compare ^sculus, Amygdalus, Prunus, Erica, 
Qtiercus, Salix. Also many hybrids of Fuchsia 
and Calceolaria are said to be constant. The 
Rhododendron hybrids are partly true to seed 
and partly variable. The progeny of the crosses 
of Vitis, Pyrus, and Cratsegus, on the other hand, 
seem to be very variable. 

h. The several forms in which some primary 
hybrids appear seem to be unsettled in the prog- 
eny. In Dianthus, according to Gartner, the 
"exception types," when sown, mostly return to 
the normal mongrel form. The various primary 
forms of the hybrids of Hieracium, Mendel found 
to be true to seed. 

e. C. F. von Gartner and other botanists have 



240 BOEROWED OPINIONS. 

made the assertion that the progeny of hybrids 
becomes, from generation to generation, weaker 
and less frnitfnl. It is certain that their growth, 
which Avas at first increased, gradually decreases 
when they fertilize themselves. Gartner's experi- 
ments, however, were made on a very small scale, 
so that his hybrids were influenced not only by 
close in-breeding, but also by the various circum- 
stances which so often result in the loss of garden 
plants cultivated only in small numbers. Even 
Gartner noticed exceptions, as in Aquilegia, Dian- 
thus barbatus x Chinensis, D. Armeria x del- 
toides. Crosses of closely related species evidently 
can be continually propagated or kept up with 
ease ; compare Brassica, Melandrium, Medicago, 
Petunia. Many gardeners assert with much con- 
fidence that many liybrids can be propagated very 
well for several generations by means of seeds ; 
comjDare Erica, Lychnis, Primula Auricula x hir- 
suta. Datura. Many observations of wild plants 
seem to confirm this view. The principle has also 
been laid down that the fruitfulness of hybrids 
increases again in later generations. It does not, 
however, appear that this rule can have a very 
broad application. It is much more probable that 
single fruitful specimens arise among hybrids, 
which can easily reproduce themselves under favor- 
able external conditions by inheriting this pe- 
culiarity. Fruitful descendants of hybrids are 



FOCKE ON THE PKOGENY OF CllOSSES. 241 

probably sometimes the product of derivative 
hybridization. 

d. Complete reversions to the parent forms 
without the aid of pollen from parent forms arise 
only in crosses of closely related races. Even in 
such crosses, true reversions only seldom take 
place, e.g.^ Phaseolus. 

e. From the variable progeny of fruitful crosses 
a few principal types often arise after a few — per- 
haps three or four — generations. If one protects 
these new types from crossing, they tend to be- 
come constant or fixed. Scientific trials or exper- 
iments which confirm this statement have been 
made only to a small extent, especially by Lecoq 
in Mirabilis, by Gordon in Linaria and especially 
in Datura. These gardeners have produced many 
new races by the crossing of related species and 
well-fixed races. Also many wild, fixed, inter- 
mediate forms may have arisen in this manner ; 
compare Brassica, Lychnis, Zinnia, Primula, Petu- 
nia, Nicotiana commutata, Pentstemon, Mentha, 
Lamium. The new types of the descendants of 
crosses frequently differ in some characteristic 
from both parent forms. My Nicotiana rustica 

X paniculata had in the second and third genera- 
tions, on the Avhole, much smaller leaves than 
either of the parent forms. 

/. The sterility and inconstancy of the progeny 
of hybrids have often led botanists to conclusions 



242 BOEROWED OPINIONS. 

which are not confirmed by experience. It is 
entirely wrong, as can he seen by the facts whicli 
have been stated, to assert that all crosses would 
necessarily soon be lost on account of these char- 
acteristics which have been promiscuously ascribed 
to them. The unsettled forms arising from crosses 
are the plastic material out of which not only 
gardeners form their new varieties, but which 
material is biologically the more valuable as it 
furnishes new species in the household of nature. 



2. Derivative Hybridization of Crosses tvith the 
Parent Forms. 

As long as one laid much stress upon the male 
or female influence wdiicli one or the other parent 
species may have had upon the hybrid, a differ- 
ence was carefully made between the advancing 
hybrid forms, or those which more closely resem- 
bled the male parent, and the degenerating 
hybrid forms, or those which more closely resem- 
bled the female parent. But these differences 
are, according to experiments that have been 
made, of very subordinate importance, or, per- 
haps, of none at all. 

By treating hybrids with parental pollen, one 
obtains, as a rule, a rather varied progeny. The 



FOCKE ON DERIVATIVE HYBRIDS. 243 

intermediate form between tlie hybrid and respec- 
tive pareiit is apt to be more numerous and more 
fruitful. Besides this, there are formed a less 
number of individuals, some of which resemble 
the hybrid, and some the parent species. Both 
are apt to be but slightly fruitful. 

The three-fourths hybrids, (A x B) 9 x A ^ , 
are often quite fruitful with their own pollen and 
appear to give races true to seed easier than the 
original hybrid ; compare iEgilops speltieformis. 
Gartner observed frequently that in later genera- 
tions the pollen became more regular and the 
fruitfulness greater, as in Dianthus (Chinensis 
barbatus) x barbatus, and also in other three- 
fourths hybrids of Diantlius, Lavatera, and 
Nicotiana. 

If one treats the three-fourths hybrid (A x B) 9 
X A ^ again with pollen from A, tlien he 
obtains a seven-eighths hybrid, or the third 
hybridized generation, which, as a rule, is very 
much like the parent which furnished the seven- 
eighths part, but it is still apt to show marked 
differences in form and fruitfulness in some indi- 
viduals. The last traces of the one original 
parent species disappears mostly in the fourth, 
fifth, or even sixth hybridized generation. 

Kolreuter and Gartner have completed the 
transition of one parent species into the other in 
many cases. They found that for a complete 



244 BORROWED OPINIONS. 

change, three to six generations were necessary — 
as a rule, four to five. Evidently the greater or 
less duration of the change depends more or less 
upon surrounding circumstances. Gordon found 
that Melandrium album x rubrum was like the 
parent species in the second generation, when 
fertilized with its own pollen, while Gartner 
found three to four generations necessary to 
bring the one into the other by means of parental 
pollen. 

As a rule, the products of the fertilization of a 
parent species with pollen from a hybrid, as 
A 9 X (A X B) ^ , are similar to those of the 
opposite cross ; nevertheless the statements of 
observers agree that the variety of forms is apt 
to be greater when one uses the hybrid as the 
male element ; compare Dianthus and Salix. 

There appears, in the products of derivative 
hybrids of crosses, as among the direct progeny, 
new characteristics, which are lacking in the 
parent forms, but are for the most part found in 
related races or species. 

3. ITi/brids of Several Sjjecies. 

a. Triple Hybrids. 

In the first years of his experience, Kolreuter 
succeeded in uniting three entirely different Nico- 
tiana species into one hybrid form. The simplest 



FOCKE ON MULTIPLE HYBRIDS. 245 

formulas according to which such a union couhl 
take pkce are: (A x B) 9 x C ^ , C 9 x (A x B) ^ , 
and (A x B) 9 x (A x C^ ) ^ . In the genera 
Dianthus, Pehirgonium, Begonia, Rhododendron, 
Nicotiana, Achimenes, Calceolaria, Salix, Hippeas- 
trum. Gladiolus, and a few others, there has been 
made a number of such unions without any par- 
ticular difficulty. One must nevertheless deter- 
mine if he unites three essentially different species, 
or if two of the factors, or even all three are only 
closely related to each other. There are similar 
but evidently different species which, in crossings 
among themselves, behave almost like races of the 
same species, as for example : — 

Melandrium album and rubrum. 

Vitis vinifera, cordifolia, aestivalis and Labrusca. 

Lobelia fulgens, splendens, and cardinalis. 

Rhododendron Ponticum, arboreum and Cataw- 
biense. 

R. flavum, viscosum, nudiflorum, and calendu- 
laceum. 

Berberis Aquifolium, and the most closely 
related species. 

Hybrids between the crosses of two species of 
these groups with the third species of the same 
genus, can no more be called true triple hybrids 
than crosses of species belonging to some smaller 
or narrower group of Vitis, Lobelia, and Rhodo- 
dendron. True triple hybrids which have been 



246 BORE OWED OPINIOKS. 

formed from three essentially different species are 
apt to be much varied in form, especially if the 
male parent species was a hybrid. On the other 
hand, in those unions wliich are most easily formed 
and are made by the formula (A x B) 9 X C ^ , 
the type of C is apt to predominate strongly, 
as, for instance, Nicotiana (rustica x paniculata) 9 
X Longsdorffii ^ , Achimenes (grandiflora x Can- 
dida) 9 X longiflora ^ , and other Gesneraceae. 

The hybrids of Erica are said to produce just as 
uniform a progeny as the pure species. Several 
Salix hybrids have acted in the same manner. 

For gardeners, therefore, the triple hybrids in 
some genera (as in Pelargonium, Begonia, Rhodo- 
dendron, Achimenes, Isoloma, Cypripedium, Gladi- 
olus) are very valuable. If they produce seeds, 
their progeny is very variable. 

h. Hybrids of Four to Six Species. 

If one does not count the crossings of very 
nearly related species (as Vitis, Rhododendron, 
etc.), these hybrids of four or more parent forms 
are somewhat rare. We know them especially in 
the genera Dianthus, Pelargonium, Begonia, Rho- 
dodendron, Nicotiana, Salix, Hippeastrum, Gladi- 
olus. The artificial union of different species in 
a single hybrid form has been carried farthest by 
Wichura, who united six Salix species. 



FOCKE ON CROSS-BREEDS AND HYBRIDS. 247 

c. Crosses of Plarits Grown Together. 

In some genera, as Pelargonium, Fuchsia, Be- 
gonia, Rosa, Erica, Rliodoclendron, Achimenes, Cal- 
ceolaria, Gladiolus, Hippeastrum, gardeners have 
crossed species and hybrids in the most manifold 
manner, intentionally and unintentionally, and 
have used the most promising forms obtained for 
further propagation. The progeny of this com- 
plex crossing is naturally almost always very vari- 
able. There appear, however, to be exceptions to 
this rule ; SAveet plainly asserts that one ahvays 
obtains the same cross from the crossing of some 
complex Pelargonium hybrids. Such constant 
complicated hybrids are, according to him, P. 
(hyb.) involucratum x (hyb.) ignescens and P. 
(hyb.) Most}' me x (hyb.) ignescens. That the 
Erica and some Salix hybrids produce a uniform 
progeny has already been mentioned. 

III. CROSS-BREEDS AND HYBRIDS. 

According to usage, we designate unions of tAvo 
different varieties of one species as cross-breeds, 
unions of two different species as h3^brids. It is 
necessary, on account of the indefiniteness of the 
term "variety," to remember that only varieties 
true to seed, or races and sub-species, can bequeath 
their characteristics Avith any degree of certainty ; 



248 BORKOWED OPINIONS. 

inconstant species, which are so often designated 
as varieties, are not considered in the theory of 
hybridization. 

Many writers have taken great pains to find a 
difference between cross-breeds and hybrids ; they 
hekl firmly to tlie hope that by means of trials in 
crossing a boundary between species and sub- 
species could be formed. Gartner, who expresses 
himself plainly in several parts of his work that the 
appearance of crosses clearly proves the specific 
differences of relationships of the parent forms, 
becomes very reticent as soon as he attempts, on 
pages 574-582, connectedly to unfold the princi- 
ples of "variety hybrids." Herbert and Naudin 
have formed the 0]3inion, after their many experi- 
ments, that it is impossible to draw the line be- 
tween cross-breeds and hybrids ; but, nevertheless, 
later botanists have again tried to find j)recise dif- 
ferences between them. 

The following propositions have been made : — 

1. The pollen of cross-breeds is normal : hy- 
brids have a greater or less number of imperfectly 
formed grains in their pollen. 

2. The fruit fulness of cross-breeds is normal : 
that of hybrids plainly diminished. 

3. Hybrids of two species wdth differently col- 
ored blossoms produce flowers of mixed or uni- 
formly modified colors : plants with irregular, 
mottled flowers have always been produced by 



FOCKE ON CROSS-BREEDS AND HYBRIDS. 249 

the crossing of varieties. It is the same with the 
coloring, marking, covering of the fruits, and 
other characteristics. 

4. Cross-breeds have a strong inclination to 
return to the parent form in later generations. 

These four propositions are in the main correct, 
but they offer little help, in a case of doubt, to a 
right decision as to specific merits. The cross of 
the red and white Anagallis arvensis would have 
to be considered as a hybrid on account of its pol- 
len, and as a cross-breed on account of the appear- 
ance of flowers of two colors. In Datura, crosses, 
which in other respects are plainly characterized 
as hybrids, easily show complete returns to the 
parent forms. Hybrids whose f ruitfulness appears 
to be in no wa}^ diminished have already been men- 
tioned (page 229). One can, consequently, make 
the rule, that crosses of closely related races are 
apt to show the characteristics ascribed to cross- 
breeds, but it is impossible by that means to es- 
tablish any sharp line between race crosses and 
species hybrids. 

Usually a few other characteristics are ascribed 
to cross-breeds by which they are distinguished 
from the hybrids of species. Gartner has asserted 
that cross-breeds of like descent are even in the 
first generation very dissimilar, while hybrids of 
the first generation are always very uniform. 
This assertion, which is also repeated by others, 



250 BORROWED OPINIONS. 

is entirely wrong. The polymorphism of the hy- 
brids of the species of Abntilon, Passiflora, Hiera- 
cium, etc., has already been shown, while, on the 
other hand, the crosses of races, in the first gener- 
ation, are usually just as uniform as the real hy- 
brids. Again, it has sometimes been asserted that 
the "varieties" of one and the same species, when 
crossed with another species, always produce the 
same hybrid forms. Gartner, especially, has laid 
particular stress upon this supposed behavior of 
varieties, although he must have known that K61- 
reuter had already observed the inheritance of 
color of the blossom in the races of Mirabilis, 
Dianthus, and Verbascum, tlie doubling of flowers 
in Aquilegia and Dianthus, the carriage and form 
of the leaf in the races of Nicotiana Tabacum and 
Hibiscus. The white-blossoming Datura ferox 
gives with D. Stramonium a white-blooming cross, 
and with the smooth-fruited race (var. Bertolonii) 
of the same species, a blue -blossoming cross. 
Nymphsea Lotus x rubra is different from N. 
Lotus X dentata. It cannot be in the least doubt- 
ful that the inheritable characteristics of races and 
so-called varieties are also bequeathed to their 
progeny. 

One will hardly go wrong if he assumes that 
Gartner came to make this rule about the be- 
havior of varieties through the behavior of unfixed 
garden crosses and garden sorts. It is a matter 



FOCKE ON CROSS-BREEDS AND HYBRIDS. 251 

of covirse that forms which show themselves un- 
fixed in their normal progeny should produce 
polymorphous hybrids, and that unfixed variety- 
signs are apt to disappear entirely in the products 
of crossing with pure species. 

The true situation is, in short, as follows : — 
The nearer the morphological and systematic rela- 
tionship of the parent forms is, the less the sexual 
capacity of reproduction in the cross is apt to 
depart from the normal direction ; the greater the 
difference between the parent forms, the more, on 
the average, is the fruitfulness of the cross weak- 
ened. Exceptions are not rare. 

The nearer the parent forms are related to each, 
other, the oftener the progeny of crosses show 
complete returns to the parent forms. 

Crosses from nearly related parent forms some- 
times show in their blossoms and fruits the pe- 
culiar characteristics of the parent forms unmixed 
beside each other ; this rarely takes place in crosses 
whose parent forms were considerably different. 
Most unsymmetrically colored flowers (Mirabilis, 
Camellia, Mimulus, Petunia, etc.) first originated 
in the progeny of crosses. 



LECTURE V. 



POLLINATION; OR HOW TO CROSS PLANTS. 



1. The Structure of the Flower. 

Pollination is the act of conveying pollen from 
the anther to the stigma. It is the manual part 
of the crossing of plants. The word fertilization 
is often used in a like sense, although erroneously; 
for it is the office of the pollen, not of the opera- 
tor, to fertilize or fecundate that j^art of the flower 
which is to develop into a seed. 

The chief requirement in pollinating flowers is 
to know the parts of the flower itself. The con- 




FiG. 1. —Bell-flower. 



spicuous or showy part of the flower is the envelope^ 
which is endlessly modified in size, form, and color. 

252 



STRUCTURE OF THE FLOWER. 



258 



This envelope protects the inner or essential organs, 
and it also attracts insects, which often perform the 
labor of pollination. This floral envelope is usn- 
ally of two series or parts, — an outer and commonly 
green series known as the calyx^ and an inner 
and generally more showy series known as the 
corolla. These two se- 
ries are well shown in 
the bell-flower, Fig. 1. 
The calyx, with its re- 
flexed lobes, is at C. 
and the large bell-form 
portion is the corolla. 
When the calyx is com- 
posed of separate parts 
or leaves, each part is 
called a sepal; in like 
manner each separate 
part of the corolla is 
a petal. In the lily, 
Fig, 2, there is no dis- 
tinction between calyx 
and corolla ; or, it may 
be said, the calyx is wanting. These envelopes 
of the flower are often much disguised. This is 
particularly true in the orchids, one of which, a 
lady-slipper, is illustrated in P^ig. 3. The sepals 
are seen at DD. They are apparently only two, 
but there is reason to believe that the lower sepal 




Fig. 2. — Flower of white lily. 



254 



POLLINATION. 



is really made up of a union of two. The three 
inner leaves are the petals, the lower one, H, 
being enlarged into the sac or slipper. 

The most important organs of the flower, how- 
ever, to one who washes to make crosses, are. the 
so-called sexual organs, the stamens and pistils. 

They can be readily 
distinguished in the 
lily, Fig. 2. The 
six bodies shown at 
S are the ends of 
the stame7is, or so- 
called male organs. 
These stamens gen- 
erally have a stalk 
or stem, known as a 
filament^ and the en- 
larged tip as the 
anther. It is in this 
anther that the pol- 
len is borne. The 
pollen is generally 
made up of very mi- 
nute yellow or brown- 
ish grains, although 
it is sometimes in the form of a more or less glu- 
tinous or adhesive mass, as in the milk-Aveeds and 
orchids. The irritating dust which falls from the 
corn tassels at the later cultivatings is the pollen. 




Fig. 3. — Flower of greenhouse 
cypripedium. 



THE ESSENTIAL ORGANS. 255 

The pistil, or so-called female organ, is shown at 
OP, Fig. 2. The enlarged portion at () is the 
ovary, wliich will develop into the seed-pod. The 
stigma, or the enlarged and roughened part which 
receives the pollen, is at P. Between these two 
parts is the slender style, a portion which is absent 
in many flowers. 

The stamens and pistils are known as the essen- 
tial 07'gans of the flower, for, whilst the calyx and 
corolla may be entirely absent, either one or both 
of these organs is present ; and these are the parts 
which are directly concerned in the reproduction 
of the species. Like the floral envelopes, these 
essential organs are often greatly modified, so 
much so that botanists are sometimes perplexed 
to distinguish them from each other or from mod- 
ified forms of the petals or sepals. The particu- 
lar features of these organs which the plant-breeder 
must be able to distinguish are the anther and the 
stigma; for the anther bears the pollen, and the 
stigma must receive it. In Fig. 1, the stamens 
are shown at E. In the flower A, which has just 
expanded, these stamens are rigid and in condition 
to shed the pollen, but in the flower B, they have 
shed the pollen and have collapsed. The stigma 
in this case is divided into three parts, but when 
the flower first opens, these parts are closed to- 
gether, H in flower A, so that it is impossible 
that they receive any pollen from the same flower ; 



256 



POLLIKATION. 



when the stamens have withered, however, as in 
B, the stigma, H, spreads open and is ready to 




Fig. 4. — Flower of night-blooming cereus. 

receive any pollen which may be brought to it by 
insects or other agencies. In this case, the ovary 



THE ESSENTIAL ORGANS. 257 

or young seecl-pod, which is in the bottom of the 
flower, is not shown in the engraving. 

Some of the particular forms of essential organs 
are well illustrated in the accompanying photo- 
graphs. In the night-blooming cereus, Fig. 4, 
the many-rayed stigma is shown just below the 




Fig. 5. — Flower of the shrubby hibiscus (Hibiscus Syriacus). 

centre of the mouth of the flower, and the nu- 
merous stamens are arranged in a circular manner 
outside of it. The mau}^ petals and numerous 
spreading sepals are also well shown. The hibis- 
cus. Fig. 5, has a central column with the anthers 
hanging upon it, and a large stigma raised beyond 



258 



POLLINATION. 




Fig. 6. — Bugbane (Cimicifuga 
raceinosa). 



them. The wild bugbane, 
or cimicifuga, is seen in 
Fig. 6, natural size. Here 
is a long spike or cluster 
of flowers. At the top 
are the unopened buds, in 
the centre the expanded 
flowers with the floral 
envelopes fallen away, — 
the fringe-like stamens 
very prominent, — and 
below are seen the pis- 
tils, the stamens having 
fallen. These pistils will 
now ripen into pods, but 
the tip-like stigma may 
still be seen on them. 
The stamens and the long 
protruding style, tipped 
with its stigma, are also 
shown in the fuchsia, 
Fip\ 15. The essential 
organs of orchids are cu- 
riously disguised. They 
are combined into a sin- 
gle body. In the lady- 
slipper. Fig. 3, the lip-like 
stigma is shown at P. 
Upon either side, at its 



STAMINATE AND PISTILLATE FLOWERS. . 259 

base, is an anther S. Projecting over the stigma 
is a greenish hidle-like body, T, which is a trans- 
formed and sterile anther. In all lady-slippers, 
these organs are essentially the same as in the 
drawing, although they vary mucli in size and 
shape ; but in most other orchids, the two side 
anthers, S, are wholly wanting, and the terminai 
organ, T, is a pollen-bearing anther. Li numer- 
ous plants, there are many distinct pistils in each 
flower. Such is the case in the strawberry, where 
each little yellow ''seed" on the ri23ened berry 
represents a pistil ; and the blackberry and the 
raspberry, where each little grain or drupelet of 
the fruit stands for the same organ. A flowering 
raspberry is illustrated natural size in Fig. 7, for 
the purpose of showing the ring of many anthers 
near the centre of the flower, inside of Avhich, in 
the very centre, is a little head of pistils. 

It frequently occurs that the stamens and pistils 
are borne in different flowers, rather than together 
in the same flower as they are in the examples 
Avhich we have studied. In these cases the flower 
is said to be staminate, or male or sterile, in one 
case, and pistillate, female or fertile, in the other 
case. If these two kinds of flowers are borne 
together upon the same plant, as in pumpkins, 
melons, cucumbers, chestnuts, oaks, and begonias, 
the plant is said to be monoecious ; but if the stami- 
nate and pistillate flowers are on entirely different 



260 POLLINATION. 

plants, as in willows and poplars, the plant is dioe- 
cious. The two kinds of squash flowers are 
shown in Fig. 8. The pistillate flower is on 
the left, and it is at once distinguished by the 
ovary or little squash below the colored portion, 




Fig. 7. — Blossom of flowering raspberry (Rubus odoratus). 

or corolla of the flower. The lobed stigma is 
seen in the centre. The staminate flower is on 
the right. It has a longer stem, no ovary, and the 
anthers are united into a conspicuous cone in the 
centre. The flowers expand early in the morning. 
Insects carry pollen to the pistillate flower, which 



STAMINATE AND PISTILLATE FLOWEES. 261 

then begins to set its fruit, whilst the staminate 
flower dies. The flowers of the common wild 
clematis are shown in Fig. 9. Upon the right 




Fig. 8. — Squash flowers of each sex. 

are the sterile flowers, which are wholly stami- 
nate. On the left, the flowers with larger sepals 
— the petals are absent — have a cone of pistils in 



262 



POLLINATION. 



the centre, and a few short and sterile stamens 
spreadmg from the base of the cone. These dif- 
ferent flowers are borne on different plants in this 
species of clematis, and the plants are therefore 
practically dioecious, because the stamens of the 
pistillate flowers generally bear no pollen. A sim- 
ilar mixed arrangement occurs in some strawber- 





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^^^^^^^^j^^Sj'^^^i^'i^^^l^^M 


I'^m 


^^^^^HHHpjj^ "^^^^^■Hj^^BV* ^k. .^.^J^I^^Skl^^T^^ ' \^ 




^^^^Sl 







Fig. 9. — Flowers of clematis (Clematis Virgiuiana). 



ries, except that there are no purely staminate 
flowers. There are purely pistillate varieties, 
others, like the Crescent, Avith a few nearly or 
quite abortive stamens at the base of the cone of 
pistils, and others in Avhich the flowers are per- 
fect or hermaphrodite, that is, containing the two 
sexes. 



COMPOSITOUS FLOWERS. 263 

The compositous flowers — like the asters, daisies, 
goldeiirods, sunflowers, dahlias, zinnias, chrysan- 
themums, and their kin — need to be considered 
in still a different category. In these plants, the 
head, or so-called flower, is an aggregation of sev- 
eral or many small flowers or florets. Each seed 
in a sunflower head, for example, represents a dis- 
tinct flower. Sometimes all of these flowers are 
perfect, — contain the two sexes, — and sometimes 
they are pistillate or staminate in different parts 
of the head ; and in some cases the plants are 
dioecious. In many plants of the composite fam- 
ily, the flowers near the border of the head are 
unlike those of the centre or disc, in having a 
long ray-like corolla ; and these ray-flowers are 
frequently of different form from the others in the 
character of the essential organs. Very frequently 
the ray-flowers are pistillate, whilst the disc-flow- 
ers are generally hermaphrodite. The anthers, in 
these plants, are united in a ring closely about the 
style and below the stigma. 

The ovary, as we have seen, ripens into the 
pod, berry, or other fruit ; but it is not able to 
bear seeds until it is assisted by the pollen. The 
pollen falls upon the roughish or sticky surface 
of the stigma, and there germinates or sends a 
minute tube dov^nwards through the style and 
finally reaches the ovule, which, when fertilized, 
rapidly ripens into the seed. The nature of this 



264 POLLINATION. 

fecundation is not germane to the present subject ; 
but it may be said that only one pollen grain is 
necessary to the fertilization of a single ovule, but 
the addition of a superabundance of pollen greatly 
stimulates the growth of the fleshy or enveloping 
parts of the fruit. It is important that the person 
who desires to cross plants should become familar 
with the stigma when it is "ripe," receptive, or 
ready to receive the pollen. This condition is gen- 
erally indicated by the glutinous or sticky or moist 
condition of the stigma, or in those stigmas which 
are not glutinous it is told by the appearing of a 
distinctly roughened or papillose condition. This 
receptive condition generally occurs about as soon 
as the flower opens. If pollen is withheld, the 
stigma will remain receptive much longer than 
when fertilization has taken place, — in some flow- 
ers for two or three days. 

The pollen is discharged from the anther in 
various ways, but it most commonly escapes 
through a chink or crack in the side of the 
anther. Sometimes it escapes through pores at 
one end of the anther; and in other cases there 
are more elaborate mechanisms to admit of its dis- 
charge. In most plants, the anthers and stigma 
in the same flower mature at different times, so 
that close-fertilization or in-breeding is avoided. 
This is well illustrated in the bell-flower. Fig. 1. 
Here the anthers wither and die before the stig- 



PKEPARING THE FLOWERS. 265 

matic lobes open. In other cases, the stigma 
matures first, although this is not the usual con- 
dition. 

II. Manipulating the Flowers. 

AVe are now familiar with the essential principles 
in the pollination of floAvers. Before a person pro- 
ceeds to operate upon a flower with which he is 
unfamiliar, he should carefully study its structure, 
so as to be able to locate the different organs, and 
to discover when the pollen and the stigma are 
ready for the work. 

The first and last rule in the pollinating of plants 
is this : JSxercise every precautioyi to prevent any 
other polliiiatioyi than that ivhich you design to give. 
The anthers, therefore, must be removed from tlie 
flower before it opens. This removal of the anthers 
is known as emasculation . Just as soon as this 
is done, tie up the flower securely in a bag to 
protect it from foreign pollen which may be 
brought by Avind or insects. As soon as the 
stigma is ripe, remove the bag and apply the de- 
sired pollen, placing the bag on the flower again, 
where it must remain until the seeds begin to 
form. The stigma may be receptive the day fol- 
lowing emasculation, or, perhaps, not until a Aveek 
afterAvards. Much depends upon the age of the 
bud Avhen emasculation takes place. It is gener- 



266 



POLLINATION, 



ally best to delay emasculation as long as possible 
and not have the flower open ; but the operator 
must be sure that the anthers do not discharge or 
that insects do not get into the flower before he 
has emasculated it. The bud at B, in Fig. 3, is 




Fig. 10. — Tobacco flowers, showing the parts of the flower, a bud 
ready to be emasculated, and an emasculated subject. 

nearly ready to emasculate. The older buds on 
the top of the spike of bugbane, Fig. 6, are ready 
to operate upon ; and so is the bud seen at the 
left in Fig. 7. 

The manner of emasculating the flower varies 



EMASCULATING. 267 

with the operator. It is a common practice to 
clip off the anthers with a pair of small seissors, 
or to hook them ont with a bent pin or a crochet 
hook. Others use tweezers. For myself, how- 
ever, I do not like any of these methods, because 
the anthers are apt to drop into the bottom of the 
corolla, Avhere it is sometimes difficult to rescue 
them ; and if one uses tweezers, there is always 
danger that the anthers may be crushed and that 
some of the pollen may adhere to the instrument 
and contaminate future crosses. I therefore usu- 
ally cut the corolla completely off just above tlie 
ovary, with a pair of small, long-handled surgeon's 
scissors (see Fig. 12), removing everything but 
the pistil. The operation is explained in Fig. 10, 
which shows the tobacco flower. The flower at 
the left shows the pin-head stigma in the centre of 
the throat, and the five anthers surrounding it. 
The second flower is spread open for the purpose 
of shoAving these organs. The third figure is a 
bud in the right condition for operation. The 
right-hand figure shows this bud cut around with 
the points of the scissors, leaving only the pistil. 
The line at W, in Fig. 2, shows where the flower 
of the lily might be cut off. The manner of oper- 
ating upon a compositous flower is shown in the 
picture of tlie zinnia. Fig. 11. In this plant the 
outer florets of the head are pistillate, whilst those 
of the disc are perfect. It is only necessary, 



268 POLLINATION. 

therefore, to remove the central stamen-bearing 
flowers before any of them open, and to cover the 
flower up before any of the pistils near the border 




Fig. 11. — Zinnia flowers; the upper head ready for emasculation, 
the lower one showing the operation performed. 

have protruded themselves. The upper head in 
Fig. 11 shows the untreated sample, whilst the 
lower one shows the same with tlie cone of central 



EMASCULATING. 269 

flowers pulled out. This treated head should now 
be covered, to await the maturing of the stigmas. 
In many compositous plants, however, the case is 
not so simple as this, because all the flowers are 
perfect. In such cases, nearly all the florets should 
be removed from the head, and a few remaining 
ones emasculated in essentially the same manner 
as described for the tobacco, Fig. 10. Whenever 
flowers are borne in clusters, nearly all of them 
should be removed and the attention confined to 
only two or three of them. One is then more cer- 
tain of getting seeds to set. In some cases, like 
the apple cluster, only one or two flowers of any 
cluster ever set fruit, and the operator should then 
choose the two or three strongest and most prom- 
ising buds, and cut all the others off. 

Flowers which bear no stamens, as the pistillate 
flowers of squashes, strawberries, and many other 
plants, of course do not require emasculating. 
They should be tied up while in bud, however, to 
prevent the access of any foreign pollen. Indian 
corn is a case in point. The pistillate flowers are 
on the ear, each kernel of corn representing a single 
flower. The silks are the stigmas. If it is desired 
to cross corn, therefore, the ear should be covered 
before any silks are protruded, and the pollen should 
be applied some days later, when the silks are full 
grown. The staminate or male flowers are in the 
tassel. 



70 



POLLINATION 



The pollen should be derived from a flower 
which has also been protected from wind and in- 




FiG. 12. -Instruments used in pollinating flowers, natural 
Pin scalpel, scissors, lens. 



size. 



APPLYING THE POLLEN. 271 

sects, because foreign pollen may have been 
dropped upon an anther by an insect visitor and it 
may be unknowingly transferred by the operator. 
The pollen-bearing parent needs no operation, of 
course, but the flower should have been tied up 
in a bag when it was in bud. The pollen is best 
obtained by picking off a ripe anther and crush- 
ing it upon the thumb-nail. Then it is trans- 
ferred to the stigma by a tiny scalpel made by 
hammering out the small end of a pin, as shown, 
full size, at the left in Fig. 12. The stigma 
should be entirely covey^ed with the pollen, if pos- 
sible. It is often advised to use a camel's hair 




Fig. 13. — Ladle for pollinating house tomatoes. 

brush to transfer the pollen, but much of the 
pollen sticks amongst the hairs of the brush and 
is ready to contaminate a future cross ; and where 
the pollen is scarce it cannot be conserved to 
advantage by a brush. In some cases the pollen 
is discharged so freely that the anther may be 
rubbed upon the stigma, or even shaken over it, 
but in most instances it will be necessary to actu- 
ally place the pollen upon the stigma with some 
hard instrument. When pollinating house-grown 
melons and cucumbers, the staminate flower is 
broken off, the corolla stripped back, and the 



272 



POLLINATION. 



antlier-cone inserted into the pistillate flower, 
where it is allowed to remain until it dries and 
falls aw^ay. In pollinating honse tomatoes, an 
implement shown in Fig. 13, one-third size, is 
nsed. This is simply a watch-glass, T, secured 
to a handle. When the honse 
is dry, at midday, the watch- 
glass is held under the flowers, 
which are tapped, and the pol- 
len falls into the glass. The 
glass is then held up under 
another flower until the stigma 
rests in the pollen. It should 
be said, however, that this pol- 
lination of tomatoes is for the 
purpose of making the fruit 
set in the absence of insects, 
not to effect a cross. If the 
latter purpose were the object 
sought, the flowers which are 
to bear the seeds would need 
to be emasculated. 
Sometimes it is impossible to secure the pollen 
at the time the stigma is ready. In some cases 
of this kind, the intended parents can be groAvn 
under glass so as to bring them into bloom at the 
same time. In other cases, it is necessary to keep 
the pollen for some time. The length of time 
that pollen will keep varies with the species and 




l^ — "~^^^"^1(pl3*' 



Fig. 14. — Bag lor cov- 
ering the flowers. 



KEEPING THE POLLEN. 



273 



probably also with the strength and vigor of the 
plant which bears it. As a rule, it will not keep 
.more than a week or two, and, in general, it may 




Fig. 15. — Fuchsias, showing the staineus and instils, and a bud 
ready to be emasculated. 

be said that the fresher it is the better it may be 
expected to act. It is best kept in dry and tight 



274 



POLLINATION. 



paper bags, such as are used for covering the 
flowers. 

Something more should be said about the bags 
which are used for covering the flowers. After 
having tried every kind which is recommended, 
I find grocer's manilla bags much the most satis- 
factory. For most flowers the four-ounce size is 
the handiest. When the bags are still flat, as 




Fig. W. — Fuchsia flower emasculated. 



they come from the packages, a hole is made 
through the two overlapping folds near the open- 
ing, and a string is passed through it and then 
tied at one of the folds, as shown in Fig. 14. 
The bag is then ready for use. Before it is put 
on the flower, the lower end of it is dij^ped in 
water to soften it so that it can be puckered 
tightly about the stem and thereby prevent the 



BAGGIJsG THE FLOWER. 



275 



entrance of any in- 
sect. A bag is put 
upon the seed- bear- 
ing flower when 
emasculation is per- 
formed, and upon 
the intended pol- 
len parent when 
the flower is still 
in bud. The bag 
may be removed 
from the emascu- 
lated floW'Cr from 
time to time to ex- 
amine the stigma, 
and again 
the pollen 
plied ; but it should 
not be taken off 
permanently until 
the pod or fruit 
begins to grow. 

By way of re- 
capitulation, let us 
consider the cross- 
ing of a fuchsia Fig. it 
flower. In Fig. 15 
two flowers are shown in full bloom, with the long 
style and the eight shorter stamens. The single 



when 
is ap- 




Fuchsia flower tied up after 
emasculation. 



276 



POLLINATIOK. 



bud is just the right age to emasculate. We 
therefore cut off the two flowers and emasculate 
the bud, as in Fig. 16. The ]3ollen of another 
flower is applied and the bag is tied on, as seen in 
Fig. 17. The best label is a small merchandise 
tag, and this records the staminate parent and 
the date. 

It will be seen that in the operation of emascu- 
lating the fuchsia flower we cut off the sepals as 





Fig. 18. — Tomato and quince, showing how the sepals were cut off 

in emasculating. 



well as the petals. In some plants the calyx 
adheres to the full-grown fruit, as on the apple, 
pear, quince, gooseberry, or persists at the base 
of the fruit, as in the tomato, pea, raspberry. In 
these fruits, therefore, the cutting aAvay of the 
calyx leaves an indelible mark which at once dis- 
tinguishes the fruits which have been crossed. 



CROSSING IN FLOWERLESS PLANTS. 



277 



even if the labels are lost. In Fig. 18 a tomato 
and quince are shown which are thus marked. 

All the foregoing remarks do not apply to the 
crossing of ferns, lycopods, and the like, because 
these plants have no flowers ; yet cross-fertiliza- 
tion may take place in them. When the spores 




Fig. 19. — Pollinating kit. 

of these flowerless plants are sown, a thin green 
tissue, or prothallus, appears and spreads over the 
ground. In this tissue the separate sex-organs 
appear, and after fecundation takes place, the 
fern, as we commonly understand it, springs forth. 
Thereafter, this fern lives an asexual life and 



278 



POLLINATION. 



produces spores year after year ; but it is only in 
this primitive protliallic stage that fertilization 
takes place, once in the lifetime of the plant. If 
these plants are to be crossed, the only procedure 
open to the gardener is to sow the spores of the 
intended parents together in the hope that a nat- 
ural mixing may take place. There are various 
well-authenticated fern hybrids. 

The pollination of flowers is such a simple work 
that few implements are required for its easy 
performance. Great care is more important than 











Fig. 20. — PoUmatiiiff kit. 



any number of tools. Every one who expects to 
cross plants should provide himself with the three 
instruments shown in Fig. 12, — a pin scalpel, 
sharp-pointed scissors, and a large hand-lens. If 
one contemplates much experimenting in this 
direction, however, it is economy of time to have 
some sort of a box in which there are compart- 
ments for the various necessities. These various 
compartments suggest at once whatever accesso- 
ries are wanting, and they hold a sufficient supply 



IMPLEMENTS USED IN CROSSING. 279 

for several hundred operations. There should 
be a compartment for bags, string, lens, scissors, 
and pencils, tags, note-book, and the like. Figs. 
19 and 20 show a convenient case for an experi- 
menter, and one which I have used with satisfac- 
tion for several years. This kit is twelve inches 
long, nine inches wide, and three inches deep. 

The chances of success in pollinating are dis- 
cussed in Lecture II. (page 83). 



GLOSSARY. 

1. The Flower. 

Anther. — That portion of the stamen which bears the 
pollen. It is the uppermost portion of the stamen. 

Calyx. — The outer series of floral envelopes, usually 
green. The various separate parts of the calyx are 
sepals. 

Corolla. — The inner series of floral envelopes, usually 
colored and forming the showy part of the flower. If 
it is divided into separate parts, these are called petals. 

Essential organs. — The stamens and pistils. 

Female. — Said of flowers which have only pistils or the 
seed-bearing part, or of plants which bear only such 
flowers ; applied also to the pistils in any flower. 

Filament. — The stalk or stem of a stamen, bearing the 
anther. 

Floral envelopes. — The calyx and corolla. 

Male. — Said of flowers which bear only stamens, or of 
plants which have only staminate flowers ; also applied 
to the stamens or pollen-bearing organs of flowers. 

Ovary. — The lowest part of the pistil, containing the 
ovules. It is the most thickened portion of the pistil, 
and it may stand either below or above the petals. 
The ovary ripens into the fruit. 

Ovule. — A body in the ovary which ripens into a seed. 

Pet'-al. — The separate portions or leaves of the corolla. 

Pistil. — The seed-bearing organ of the flower. It always 
comprises two parts, the ovary — which becomes the 
pod or fruit — and the stigma. Usually there is a 

281 



282 GLOSSARY. 

style connecting the two. Often called the fertile or 
female organ. 

Pistillate. — Said of a plant or flower which has only pis- 
tils or female organs. 

Pollen. — The contents of the anther, capable of fertil- 
izing the ovules. It is usually composed of minute 
yellow or brown grains. 

Se'-pal. — The separate portions or leaves of the calyx. 

Spore. — The reproductive organ of flowerless plants, by 
means of which they propagate, as other plants propa- 
gate by means of the seed. The spore is asexual. 

Stamen. — The pollen-bearing organ of the flower. Often 
called the male or sterile organ. Its essential part is 
the anther. The stalk, when present, is called the 
filament. 

Staminate. — Said of a flower or plant which bears only 
stamens or male organs. 

Stigma. — The top end of the pistil, where the pollen 
lodges and germinates. It is usually a somewhat ex- 
panded surface, and is roughened, or sticky, or moist 
when ready to receive the pollen. 

Style. — The more or less slender portion of the pistil 
w^hich lies betw'een the stigma and ovary. The pol- 
len-tubes pass through it in reaching the ovary. 
2. Crossing. 

Bigener; higeneric-hybrid. — A hybrid between species of 
different genera. 

Bigeneric half-breed. — The product of a cross betw^een 
varieties of species of different genera. 

Close-fertilization ; self-fertilization. — The action of pollen 
upon the pistil of the same flow^er. 

Close-pollination : self-pollination. — The transfer of pollen 
to a pistil of the same flow^er. 

C7'oss. — The offspring of any two flowers which have 
been cross-fertilized. 



GLOSSARY. 



283 



Cross-hreed ; half-breed; mongrel; variety-hybrid. — Across 
between varieties of the same species. 

Cross-fertilization. — The action of pollen upon the pistil 
of another flower of the same species. 

Crossing. — The operation or practice of cross-pollinating. 

Cross-pollination. — The conveyance of pollen to the 
stigma of another flower. 

Derivative- or derivation-hybrid ; secondary-hybrid. — A hy- 
brid between hybrids, or between a hybrid and one of 

its parents. 

Fertilization ; fecundation ; impregnation. — The action of 
the pollen upon the ovules. 

Half-hybrid. — The i)roduct of a cross between a species 
and a variety of another species. 

Hybrid.- The offspring of crossed plants of different 
species. 

Hybridism ; hybridity. — The state, quality, or condition 
of being a hybrid. 

Hybridization. — The state or condition of being hybrid- 
ized, or the process or act of hybridizing. 

Hybridizing. — The operation or practice of crossing be- 
tween species. 

Individual cross. — The offspiing of two crossed flowers 
on the same plant. 

Individual fertilization. — Fertilization between flowers 
upon the same plant. 

Mongrel. — A cross. 

Mule. — A sterile (seedless) hybrid. 

Pollination. — The conveyance of pollen from the anther 
to the stigma (page 252). 

The term cross is used to denote the offspring of any 
sexual union between plants, whether of different 
species or varieties, or even different flowers upon the 
same plant. It is a general term. And the word is 



284 GLOSSARY. 

also sometimes used to denote the operation of per- 
forming or bringing about the sexual union. There 
are different kinds of crosses. One of these is the 
hybrid. A hybrid is a cross between two species, as a 
plum and a peach, or a raspberry and a blackberry. 
There has lately been some objection urged against 
this term, because it is often impossible to define the 
limitations of species, — to tell where one species ends 
and another begins. And it is a fact that this diffi- 
culty exists, for plants which some botanists regard as 
mere varieties others regard as distinct species. But 
the term hyhrid is no more inaccurate than the term 
species, upon which it rests ; and, so long as men talk 
about species, so long have we an equal right to talk 
about hybrids. Here, as everywhere, terms are mere 
conveniences, and they seldom express the whole truth. 
In common speech the word hyhrid is much misused. 
Crosses between varieties of one species are termed 
hfdf-hreeds or croKS-hreeds, and those between different 
flowers upon the same plant are called individual 
crosses. 
3. Classificatiox. 

Break. — A radical departure from the type. Ordinarily 
used in the sense of sport, but in its larger meaning it 
refers to the permanent appearance of apparently new 
or very pronounced characters in a species. 

Bud-variation. — Variation or dej^arture from a type 
through the agency of buds (pages 28, 158). 

Bud-variety. — A variety resulting from bud-variation. 
Bud-sport. 

Family (Order in botany.) — A group of genera and 
species; as Cupuliferce, the Oak Family, RosacecE, the 
Rose Family. 

Form. — A minor variety, usually transient, produced by 
some local environment. 



GLOSSARY. 285 

Genus (plural, genera^. — A group or kind comprising a 
greater or less number of closely related species; as 
Acer, the maples, Fragaria, the strawberries. 

Race. — A fixed cultural variety; that is, a cultural va- 
riety which reproduces itself more or less uniformly 
from seeds. 

Seedling. — A plant growing directly from seed, without 
the intervention of grafts, layers, or cuttings. 

Seed-variation. — Variation or departure from a type 
through the agency of seeds. 

Seed-variety. — A variety resulting from seed- variation. 

Species (plural, species). — An indefinite term applied to 
all individuals of a certain kind which come or are 
supposed to come from a common parentage. A per- 
ennial succession of normal or natural similar indi- 
viduals perpetuated by means of seedage. "All the 
descendants from the same stock." — Gray. 

Spoii. — A variety or variation which appears suddenly 
and unaccountably, either from seeds or buds ; more 
properly restricted to varieties originating from buds, 
and so used in this book. 

Stock. — The parentage of a particular strain or variety. 

Strain. — A sub-variety, or individuals of a variety, which 
has been improved and bred under known conditions. 

Variation. — 1. The act or condition of varying or be- 
coming modified. 2. A transient variety, more or less 
incapable of being fixed or rendered permanent. 

Variety. — A form or series of forms of a species marked 
by characters of less permanence or less importance 
than are the species themselves. 

Wilding. — A wild individual from a cidtivated species. 



INDEX. 



Abortive varieties, 152. 
Abutilon, crosses, 220, 233, 250. 
Accident, 154. 
Acclimatization, 24, 26. 
Acer, bud-variety, 177. 
Achimenes, crosses, 245, 246, 247. 
Acorns, bud-variety, 177. 
Acquired characters, 14. 
Adult forms, 156. 
Ji^gilops, crosses, 243. 
^sculus, bud-variety, 178. 
Jilsculus, crosses, 239. 
Agathita, bud-variety, 178. 
Ageratum, bud-varieties, 178. 
Agrostemma Coeli-rosa, dwarfs, 144. 
Albinos, 148. 
Allut, Cazalis, 211. 
Almond, bud-variety, 179. 
Alnus, crosses, 226. 
Alopecurus, crosses, 230. 
Altitude and plants, 25. 
Amelioration, gradual, 50. 
Amygdalus, crosses, 239. 
Anagallis, crosses, 222, 223, 231. 
Anemone, crosses, 224, 229. 
Anemone, varieties, 179. 
Animal and plant contrasted, 5, 91. 
Annee, 141. 

Antagonistic featui'es, 95. 
Anther, 254. 
Apple, Wealthy, 108. 
Apples, bud-variation in, 118, 175. 
Apples, hybrid, 66, 79, 111. 
Apples, races of, 90. 
Apples, variations in, 3, 27, 87, 99, 131. 
Apricot, bud-variety, 179. 
Aquilegia, crosses, 224, 229, 234, 239, 
240, 250. 



Aralla, bud-variety, 180. 
Arthur, 103, 116. 
Arundo, variation, 176, 180. 
Asexual propagation, 7. 
Aspidistra, sport, 180. 
Aster, varieties, 180. 
Atavism, 106. 
Atragene, 184. 
Atropa, crosses, 223. 
Azalea, bud-varieties, 180. 

Bag for covering flowers, 272. 

Bamboos, variation, 176. 

Banana, varieties, 175. 

Bartel, T. C, 130. 

Barteldes, 140. 

Bean, bud-variation, 176. 

Beans, types of, 135. 

Beet, crosses, 56. 

Begonia, crosses, 224, 226, 227, 229, 

230, 231, 233, 234, 239, 245, 246, 

247. 
Begonia pollinations, 86. 
Bell-flower, 252. 
Berberis, crosses, 245. 
Bigness, variation in, IS. 
Blackberry, crosses, 79, 111. 
Blackberry, introduction of. 129. 
Bletia, crosses, 222. 
Bohnhof, SO. 
Bornet, 232. 
Bouschet, Henri, 212. 
Brassica, crosses, 223, 239, 240, 241. 
Braun, Alexander, 17. 
Breaking the type, 19, 23, 93. 
Bruaut, 113. 
Buckwheat, crosses, 56. 
Budd, Professor, 133. 



287 



288 



INDEX. 



Bud-variation, 6, 21, 28, 3T, 101, 118, 

126, 153. 
Bugbane, 258. 
Burpee, 139. 
Buxus, bud-varieties, 181. 

Cabbage, crosses, 56. 

Cacti, crosses, 235. 

Calceolaria, crosses, 222, 229, 233, 234, 

239, 245, 247. 
Calceolaria plantaginea, dwarfs, 144. 
Calliopsis tinctoria, dwarfs, 144. 
Callistephus hortensis, dwarfs, 145. 
Calyx, 253. 

Camellia, bud-varieties, 182. 
Camellia, crosses, 251. 
Canar3'-grass, crosses, 57. 
Cannas, 140. 

Capsella, crosses, 226, 231. 
Carman, 79. 
Carnation, 115. 
Carriere, 96, 116, 153. 
Caspary, 229. 
Cedars, 156. 

Cephalotaxus, sports, 183. 
Cereus, bud-variety, 184. 
Cereus, crosses, 226, 230, 233, 239. 
Cereus, night-blooming, 256. 
Change of seed, 28, 59, 116. 
Checking growth, 116. 
Cheiranthus, sport of, 185. 
Cherry, hybrid, 112. 
Cherry, sports of, 171. 
Chloranthic varieties, 153. 
Chlorosis, 149. 
Choice of variations, 31. 
Chrysanthemum carinatum, 100. 
Chrysanthemum, sports of, 158. 
Cimicifuga racemosa, 258. 
Cinchona, crosses, 225. 
Cirsium, crosses, 229, 233, 239. 
Cistus, crosses, 219, 222, 231, 234. 
Clematis, crosses, 224. 
Clematis, flowers, 262. 
Clematis, varieties, 184. 
Climate and variation, 24, 114, 146. 
Coleus, sports in, 120. 
Coloration, 148. 

Colors, modified by climate, 25. 
Conifers', 156. 



Contradictory attributes, 98. 

Convolvulus pollinations, 85. 

Coreojisis tinctoria, dwarfs, 144. 

Cornus, bud-varieties, 185. 

Corolla, 253. 

Cotyledon, crosses, 229. 

Crabs, hybrid, 66, 111. 

Crataegus, crosses, 239. 

Crinum, crosses, 218, 225, 229, 232, 234. 

Cross-breeds, Focke on, 247. 

Cross, function of, 50. 

Cross, primary, 215. 

Crosses, characteristics of. 68. 

Crosses, Focke on, 215. 

Crossing a means, 107. 

Crossing and change of seed, 59. 

Crossing, limits of, 44. 

Crossing, philosophy of, 39. 

Crossing, rule for, 109. 

Crozy, 113, 140. 

Cucumber pollinations, 85. 

Cucumis, crosses, 222. 

Cucurbita Pepo, 75, 84. 

Cucurbitaceae, crosses, 46, 58, 74, 82, 

229, 230, 235. 
Cultivation, philosophy of, 22. 
Currant, sports of, 173. (See Kibes.) 
Cypripedium, 254. 
Cypripedium, crosses, 218, 227, 229, 

"246. 
C3'tisus Adami, 185. 

Dactylis, bud-variety, 185. 

Darwin, 17, 23, 32, 42, 47, 51, 54, 56, 60, 

63, 69, 72, 84, 87, 117, 119, 121, 176, 

228. 
Dating back, 106. 
Datura, crosses, 222, 223, 224, 226, 228, 

234, 239, 240, 249, 250. 
Decaisne, 229. 
De Candolle, 150, 178. 
Derivative crosses, 238. 
Dewberry crosses, 79, 111. 
Dewberry, introduction of, 129. 
Dianthus Chinensis, dwarfs, 145. 
Dianthus, crosses, 218, 219, 223, 226, 

227, 229, 233, 234, 237, 239, 240, 243, 

244, 245, 246, 250. 
Dianthus semperflorens, 156. 
Dichroism, 154. 



INDEX. 



289 



Di^talis, crosses, 218, 219, 221, 223, 

226, 227, 229, 230, 232, 237. 
Dinioi-phisui, 154. 
Dioecious plants, 260. 
Divergence of character, 28. 
Division of labor, 42. 
Doubleness in lij'brids, 237. 
Doubleness of flowers, 149. 
Dracaena, variation, 176. 
Duval, M., 167. 
Dwarfing, 25, 114, 143. 

Early varieties, 146. 
Echinocactus, sports, 186. 
Eckford, 113. 
Egg-plant, crosses, 57, 74. 
Egg-plant pollinations, 85. 
Egg-plants, variation in, 95. 
Egypt, plagues of, 40. 
Elaeagnus, bud-varieties, 186. 
Emasculation, 265. 
Envelopes, floral, 252. 
Environment and variation, 12. 
Epilobium, crosses, 218, 222, 229, 230, 

233. 
Equilibrium of organisms, 20, 61. 
Erica, crosses, 229, 233, 239, 240, 246, 

247. 
Essential organs, 255. 
Euonymus Japonicus, 156, 186. 

Fagus, fern-leaved, 187. 

Fall sowing, 115, 143. 

Ferns, crossing, 277. 

Fertility of soil, 18, 22. 

Ficus, forms of, 188. 

Filament, 254. 

Fittest, survival of, 32, 39. 

Fixation of plants, 31. 

Flavor, modified by climate, 25. 

Flon, M., 156. 

Flowerless plants, crossing, 277. 

Focke, 68, 81, 108, 215. 

Fontanesia, sport, 188. 

Food supply, 16, 116. 

Fortuitous vai-iation, 9, 

Fragaria, crosses, 229. 

Fraxinus, bud-varieties, 188. 

Fromont, 158. 

Fuchsia, crosses, 229, 233, 239, 247. 



Fuchsia flowers, 273, 274, 275. 
Function of the Cross, 50. 
Fusain, 156. 

Galium, crosses, 222. 

Gardenia, bud-variety, 189. 

Gartner, 216, 218, 219, 220, 228, 233, 

235, 239, 240, 243, 244, 248, 249, 250. 
Gazania rigens, 146. 
Genera, monotypic, 97. 
Gesneraceoe, crosses, 227, 229, 246. 
Geum, crosses, 219, 229, 239. 
Giant forms, 145. 
Gibb, Charles, 133. 
Gideon, Peter M., 108. 
Gillyflower, bud-variety, 189. 
Giraud, Desire, 166. 
Gladiolus, crosses, 226, 229, 234, 245, 

246. 
Gleditschia triacanthos, 207. 
Glossary, 282, 
Gofl^, 103. 

Gordon, 229, 241, 244. 
Gourd, crosses, 58, 74, 82. 
Grape, bud-varieties, 174, 210. 
Grapes, hybrid, 66, 78, 110, 111. 
Gray, Asa, 33, 178. 
Greenhouses, produce variation, 115. 

Hallock, V. H., & Son, 124. 

Hardy varieties, 145. 

Hartogia Capensis, 192. 

Hedera, forms of, 189. 

Helianthemum, crosses, 223, 226. 

Helichrysum bracteatum, dwarfs, 144. 

Henderson, 138. 

Herbert, 248. 

Hibiscus, bud-varieties, 190. 

Hibiscus, crosses, 225, 250, 

Hibiscus Syriacus, 257. 

Hieracium, crosses, 220, 233, 234, 237, 

239, 250. 
Hippeastrum, crosses, 226, 229, 234, 

239, 245, 246, 247. 
Holly, sports, 191. 
Horse-chestnut, bud-variety, 178. 
Husk-tomato, 60, 85. 
Hyacinth, forms, 190. 
Hybrids, characters of, 68, 215. 
Hybrids, Focke on, 215. 



290 



INDEX. 



Hybrids, multiple, 246, 247. 
Hybi-ids, rarity of, 53. 
Hybrids, seven-eighths, 243. 
Hybrids, three-fourths, 243. 
H3'brids, triple, 244. 
Hydrangea, 146, 191. 
Hymenocallis, crosses, 230. 

Iberis umbellata, dwarfs, 145. 

Ignotum tomato, 123. 

Ilex, bud-varieties, 191. 

Impatiens Balsamina, dwai-fs, 145. 

In-breeding, 72. 

Indeterminate varieties, 87. 

Individuality, causes of, 8. 

Individuality, fact of, 2. 

Instruments for pollination, 270. 

Ipomceas, colors of seeds, 104. 

Iris, bud-variety, 192. 

Isolation of the plant, 22. 

Isoloma, crosses, 226, 227, 231, 233, 

246. 
Ivy, forms of, 189. 

Jamain, M., 163. 
Jobert, M., 179. 
Joigneaux, M., 204. 
Juniperus, bud-varieties, 192. 

Klotzsch, 226, 229. 

Knight, Thomas Andrew, 17, 54, 227, 

229. 
Kohl-rabi, 80, 
Kolreuter, 54, 73, 216, 217, 219, 228, 

229, 243, 244, 250. 
Kumerle, W. J., 140. 
Kuntze, 225. 

Labor, division of, 42, 48. 
Lachaume, M., 166. 
Lactuca, crosses, 238. 
Ladle for pollinating, 271. 
Lamium, bud-variety, 192. 
Lamium, crosses, 239, 241. 
Lantana, crosses, 222. 
Large-flowered varieties, 145. 
Late varieties, 146. 
Latitude and plants, 25. 
Laurocerasus, sports, 192. 
Lavatera, crosses, 234, 239, 243. 



Leafiness, 25. 

Lecoq, 227. 

Lemoine, 113. 

Lens for pollinating, 270. 

Leptosiphon densiflorus, dwarfs, 144. 

Lettuce, crosses, 56. 

Ligustrum, sports, 193. 

Lilac, bud-varieties, 193. 

Lily, white, 253. 

Lima beans, 138. 

Limits of crossing, 44. 

Linaria, crosses, 222, 227, 238, 289, 

241. 
Lindley, 68. 
Links, missing, 41, 48. 
Linnaeus, 81, 152. 
Linum, crosses, 223. 
Lobelia, crosses, 219, 222, 232, 233, 

234, 235, 245. 
Luffa, crosses, 232. 
Lupines, heredity in, 106. 
Lychnis Coeli-rosa, dwarfs, 144. 
Lychnis, crosses, 240, 241. 
Lycium, crosses, 218, 226. 
Lycopods, crossing, 277. 

Maize, crosses, 56, 

Malle, Bureau de la, 175. 

Mamillaria, sports, 194. 

Maple, Wier's, 109. 

Meadow, plants in, 23. 

Medicago, crosses, 220, 233, 240. 

Melandrium, crosses, 220, 222, 223, 

225, 231,233, 240, 244, 245. 
Mendel, 239. 

Mentha, bud-variety, 194. 
Mentha, crosses, 229, 241. 
Mersereau, 131. 
Mimulus, crosses, 222, 251. 
Mirabilis, crosses, 222, 226, 227, 228, 

234, 241, 2.50, 251. 
Mirabilis pollinations, 85. 
Missing links, 41. 
Mixing in the hill, 118, 201. 
Molinia, bud-variety, 194. 
Monoecious plants, 259. 
Monotypic genera, 97. 
Moore, Jacob, 110. 
Morning-glory, 54. 
Morong, Dr. Thomas, 60. 



INDEX. 



291 



Morren, 149. 
Mourriere, M., 175. 
Mulbeny, Teas', 109. 
Multiple hybrids, 240, 247. 
Munson, Professor, 58. 
Munson, T. V., 79, 111. 
Musa, bud-variety, 194. 
Muskmelon pollination, 85. 
Myrtle, bud-variety, 195, 

Nanz & Neuner, 170. 

Narcissus, crosses, 220, 225, 236. 

Natal variations, 15. 

Natural selection, 32, 51. 

Naudin, 216, 229, 248. 

Nectarine, origin of, 118, 173. 

Nepenthes, crosses, 220. 

Nicotiana, crosses, 72, 217, 219, 222, 
224, 225, 226, 227, 229, 233, 234, 237, 
238, 239, 241, 243, 244, 245, 246, 250. 

Nicotiana pollinations, 85, 86. 

Nuphar, crosses, 226. 

Nymphita, crosses, 218, 225, 227, 231, 
234, 250. 

Odoriferous varieties, 147. 
(Enothera, crosses, 219, 239. 
(Enothera Drummondii, dwarfs, 144. 
Ogev, Pierre, 166. 
Olea ilicifolia, 195. 
Opuntia, bud-variety, 195. 
Orange, bud-variety, 195. 
Orchidae, crosses, 229, 233, 235. 
Orchids, hybrids, 79. 
Orontium, sport, 195. 
Osmanthus, sport, 195. 
Ovary, 255, 263. 

Palmer, Asa, 139. 

Pansy, 146. 

Papaver, crosses, 218, 224, 226, 229, 

231, 237. 
Papaver, forms of, 151. 
Pare, M., 160. 

Parents, influence of, 81, 217. 
Passiflora, crosses, 220, 226, 229, 235, 

250. 
Peach, bud-variation in, 118, 173, 196. 
Peach, hybrids, 47. 
Peaches, races of, 91. 



Pear, bud-varieties, 174, 197. 

Pears, hybrid, 66, 79, 111. 

Pears, variation in, 99. 

Peas, viney, 16. 

Pelargonium, crosses, 218, 220, 229, 

230, 233, 234, 237, 245, 246, 247. 
Pelargonium, sports in, 198. 
Peloric varieties, 152. 
Pentstemon, crosses, 241. 
Pepino pollinations, 86. 
Pepino, variation in, 95. 
Pepper, red, pollination, 85. 
Peppers, variation in, 96. 
Persica, 196. 
Petal, 253. 

Petunia, crosses, 218, 240, 241, 251. 
Petunia pollinations, 85, 86. 
Phalaris, sports, 198. 
Phaseolus, crosses, 223, 238, 241. 
Phlox, bud-varieties, 199. 
Phragmites, bud-varieties, 199. 
PhysaUs, 60. 

Physalis, variation in, 96. 
Picea, bud-vai-iety, 199, 
Pink, 156, 160. 
Pinus, bud-varieties, 199. 
Pinus, crosses, 226. 
Pistil, 255. 

Pisum, crosses, 223, 238. 
Pittosporum, sport, 200. 
Plant-breeding, 91. 
Pliny, 131. 

Plum, hybrids, 47, 112. 
Plum, sports of, 172. 
Plums, Japanese, 27. 
Podocarpus, 155, 183. 
Pollen, 254, 264. 
Pollinating kit, 277, 278. 
Pollination, 252. 
Pollination, uncertainties of, 83. 
Polymorphous varieties, 153. 
Polytypic genera, 97. 
Populus, bud-variety, 200. 
Populus, crosses, 222. 
Position, advantage of, 22. 
Post-natal variations, 15. 
Potamogeton, crosses, 227. 
Potato, 37, 117. 
Potato and tomato, 95. 
Potato, bud-varieties, 201, 209. 



292 



INDEX. 



Potato, seedlessness, 99. 
Precocious varieties, 146. 
Primula, crosses, 239, 240, 241. 
Progeny of crosses, 237. 
Proliferous varieties, 150. 
Propagation, asexual, 7. 
Pruning. 23. 

Prunus, bud-variety, 205. 
Prunus, crosses, 229, 239. 
Pumpkin, crossing, 46, 58, 74, 82. 
Pyrus, crosses, 229, 239. 

Quercus, crosses, 226, 229, 239. 
Quince, pollinated, 276. 

Races in fruits, 90. 
Eadish pollinations, 85. 
Eaphanus Kaphanistrura, 116, 231. 
Eaphanus sativus, 231. 
Easpberry, flowering, 260. 
Easpberry, hybrids, 79, 111. 
Eepresentative species, 66. 
Eetinosporas, 156. 
Eheum, bud-variety, 206. 
Ehododendron, crosses, 145, 218, 222, 
225, 226, 229, 230, 239, 245, 246, 247. 
Eibes, bud-varieties, 206. 
Eibes, crosses, 230, 233. 
Eobinia, bud-varieties, 206. 
Eogue, 89, 127. 
Eosa, 161. 

Eose, bud-varieties in, 118, 161, 207. 
Eoses, crosses, 233, 247. 
Eubus, crosses, 227, 230, 232, 234. 
Eubus odoratus, 260. 
Eunning out of varieties, 36, 125. 
Eussia, fruits from, 27, 90, 133. 
Eye, hybrids, 79. 

SalLx, bud-variety, 208. 

Salix, crosses, 219, 225, 226, 227, 229, 

231, 234, 239, 244, 245, 246, 247. 
Salter, 119. 
Salvia, crosses, 223. 
Sambucus, sports, 208. 
Satyrium hircinum, 148. 
Scabiosa atropurpurea, dwarfs, 145. 
Scalpel for pollinating, 270. 
Schizanthus retusus, dwarfs, 145. 
Scissors for pollinating, 270. 



Secondary crosses, 238. 

Seed, change of, 28, 59. 

Seeds, colors of, 104. 

Seeds, early, 147. 

Seeds, immature, 103, 147. 

Seeds, large and small, 101. 

Selection and progress, 120, 122, 127. 

Selection, natural, 32, 51. 

Self-fertilization, etfects of, 54. 

Senecio cruentus, dwarfs, 144. 

Sepal, 253. 

Seven-eighths hybrids, 243. 

Sex and variation, 11, 43. 

Silene, crosses, 234. 

Siuningia, crosses, 231. 

Solan urn, bud-varieties, 209. 

Solanum, variations in, 95. 

Spencer, 61. 

Spiraea, bud-varieties, 209. 

Sports, 22, 28, 37, 163. 

Sprengel, 54. 

Squash, crosses, 58, 74, 82. 

Squash flowers, 261. 

Squash, Hubbard, 46. 

Stamens, 254. 

Stigma, 255. 

Strawberry, Wilson, 125. 

Struggle for life, 20, 29, 39. 

Sturtevant, 103. 

Style, 255. 

Sugar-cane, varieties, 175. 

Survival of the fittest, 32, 39. 

Swamping eff"ects of inter-crossing, 46. 

Sweet, 247. 

Symphoricarpus, sport. 209. 

Symphytum, bud-varieties, 209. 

Synchronistic variations, 117. 

Tagetes, dwarfs, 145. 
Teas, 109. 

Teleology of hybrids, 236. 
Thinning, 23. 

Three-fourths hybrids, 243. 
Thuyopsis, sport, 209. 
Tillage and food supply, 17, 22. 
Timbal-Lagrave, 217. 
Toad-flax, 152. 
Tobacco flowers, 266. 
Tobacco poflinations, 86. 
Tomato and potato, 95. 



INDEX. 



293 



Tomato, crosses, 58. 
Tomato, Igiiotum, 123. 
Tomato, pollinated, 276. 
Tomato polliuatioiis, 85. 
Tomato, Troj)by, 37. 
Tomato, variation in, 98. 
Tomatoes, breeding, 103. 
Tragoi)Ogon, crosses, 238. 
Triple hybrids, 24-4. 
Tropitolum, crosses, 222, 226. 

Ulmus, bud-variety, 209. 
Ulmus, crosses, 226. 

Variability, variation in, 25. 
Variation and environment, 12. 
Variation caused by sex, 11, 43. 
Variation, fortuitous, 9. 
Variation, philosophy of, 1. 
Variations, choice of, 31. 
Variations, fixation of, 31. 
Variations, natal and post-natal, 15. 
Variations, origin of, 8, 41. [157. 

Variegation, peri)etuating, 120, 149, 
Varieties, running out, 36, 125. 
Variety, what is a, 35. 
Verbascum, crosses, 219, 221, 222, 223, 
224, 226, 229, 235, 239, 250. 



Verdier, Victor, 167. 

Verlot, 121, 143. 

Veronica, crosses, 233, 239. 

Viburnum, sports, 209. 

Vilmorin, 152. 

Vilmorin, Henri L. de, 100, 105, 

142. 
Vilmorin, Louis Leveque de, 106. 
Vine, bud-varieties, 174, 210, 
Viola, bud-variety, 210. 
Viola, crosses, 229, 231. 
Vitis, crosses, 229, 239, 245, 246. 

Walker, Ernest, 120, 169. 
Wallace, 47, 60, 67. 
Watermelon pollination, 85. 
Weismann, 13, 14. 
Wheat, hybrids, 79. 
Wichura, 216, 246. 
Wier, D. B., 109. 
Wigandia, sport, 215. 
Willdenow, 152. 

Yucca, variation, 176. 

Zinnia, crosses, 241. 
Zinnia, flovsrers, 268. 



NEW EDITION, 



The Horticulturist's Rule-Bool<, 

A COMPENDIUM OF USEFUL INFORMATION FOR FRUIT- 
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